diff --git a/custom_components/bermuda/bermuda_device.py b/custom_components/bermuda/bermuda_device.py
index 9774fa4..836b9a1 100644
--- a/custom_components/bermuda/bermuda_device.py
+++ b/custom_components/bermuda/bermuda_device.py
@@ -128,20 +128,29 @@ def __init__(self, address, options) -> None:
             else:
                 self.address_type = BDADDR_TYPE_OTHER
 
-    def set_ref_power(self, value: float):
+    def set_ref_power(self, new_ref_power: float):
         """
         Set a new reference power for this device and immediately apply
         an interim distance calculation.
+
+        This gets called by the calibration routines, but also by metadevice
+        updates, as they need to apply their own ref_power if necessary.
         """
-        self.ref_power = value
-        nearest_distance = 9999  # running tally to find closest scanner
-        nearest_scanner = None
-        for scanner in self.scanners.values():
-            rawdist = scanner.set_ref_power(value)
-            if rawdist < nearest_distance:
-                nearest_distance = rawdist
-                nearest_scanner = scanner
-        if nearest_scanner is not None:
+        if new_ref_power != self.ref_power:
+            # it's actually changed, proceed...
+            self.ref_power = new_ref_power
+            nearest_distance = 9999  # running tally to find closest scanner
+            nearest_scanner = None
+            for scanner in self.scanners.values():
+                rawdist = scanner.set_ref_power(new_ref_power)
+                if rawdist is not None and rawdist < nearest_distance:
+                    nearest_distance = rawdist
+                    nearest_scanner = scanner
+            # Even though the actual scanner should not have changed (it should
+            # remain none or a given scanner, since the relative distances won't have
+            # changed due to ref_power), we still call apply so that the new area_distance
+            # gets applied.
+            # if nearest_scanner is not None:
             self.apply_scanner_selection(nearest_scanner)
 
     def apply_scanner_selection(self, closest_scanner: BermudaDeviceScanner | None):
@@ -151,23 +160,16 @@ def apply_scanner_selection(self, closest_scanner: BermudaDeviceScanner | None):
 
         Used to apply a "winning" scanner's data to the device for setting closest Area.
         """
+        # FIXME: This might need to check if it's a metadevice source or dest, and
+        # ensure things are applied correctly. Might be a non-issue.
+        old_area = self.area_name
         if closest_scanner is not None:
             # We found a winner
-            old_area = self.area_name
             self.area_id = closest_scanner.area_id
             self.area_name = closest_scanner.area_name
             self.area_distance = closest_scanner.rssi_distance
             self.area_rssi = closest_scanner.rssi
             self.area_scanner = closest_scanner.name
-            if (old_area != self.area_name) and self.create_sensor:
-                # We check against area_name so we can know if the
-                # device's area changed names.
-                _LOGGER.debug(
-                    "Device %s was in '%s', now in '%s'",
-                    self.name,
-                    old_area,
-                    self.area_name,
-                )
         else:
             # Not close to any scanners!
             self.area_id = None
@@ -175,6 +177,14 @@ def apply_scanner_selection(self, closest_scanner: BermudaDeviceScanner | None):
             self.area_distance = None
             self.area_rssi = None
             self.area_scanner = None
+        if (old_area != self.area_name) and self.create_sensor:
+            # Our area has changed!
+            _LOGGER.debug(
+                "Device %s was in '%s', now '%s'",
+                self.name,
+                old_area,
+                self.area_name,
+            )
 
     def calculate_data(self):
         """
@@ -182,6 +192,7 @@ def calculate_data(self):
         etc can be freshly smoothed and filtered.
 
         """
+        # Run calculate_data on each child scanner of this device:
         for scanner in self.scanners.values():
             if isinstance(scanner, BermudaDeviceScanner):
                 # in issue #355 someone had an empty dict instead of a scanner object.
@@ -193,7 +204,7 @@ def calculate_data(self):
                     "scanner_not_instance", "Scanner device is not a BermudaDevice instance, skipping."
                 )
 
-        # Update whether the device has been seen recently, for device_tracker:
+        # Update whether this device has been seen recently, for device_tracker:
         if (
             self.last_seen is not None
             and MONOTONIC_TIME() - self.options.get(CONF_DEVTRACK_TIMEOUT, DEFAULT_DEVTRACK_TIMEOUT) < self.last_seen
diff --git a/custom_components/bermuda/bermuda_device_scanner.py b/custom_components/bermuda/bermuda_device_scanner.py
index 6913ce0..258b57e 100644
--- a/custom_components/bermuda/bermuda_device_scanner.py
+++ b/custom_components/bermuda/bermuda_device_scanner.py
@@ -105,6 +105,8 @@ def update_advertisement(self, scandata: BluetoothScannerDevice):
         claims to have data.
         """
         # In case the scanner has changed it's details since startup:
+        # FIXME: This should probably be a separate function that the refresh_scanners
+        # calls if necessary, rather than re-doing it every cycle.
         self.name = scandata.scanner.name
         self.area_id = self.scanner_device.area_id
         self.area_name = self.scanner_device.area_name
@@ -240,9 +242,12 @@ def _update_raw_distance(self, reading_is_new=True) -> float:
             # Add a new historical reading
             self.hist_distance.insert(0, distance)
             # don't insert into hist_distance_by_interval, that's done by the caller.
-        else:
-            # We are over-riding readings between cycles. Force the
-            # new value in-place.
+        elif self.rssi_distance is not None:
+            # We are over-riding readings between cycles.
+            # We will force the new measurement, but only if we were
+            # already showing a "current" distance, as we don't want
+            # to "freshen" a measurement that was already out of date,
+            # hence the elif not none above.
             self.rssi_distance = distance
             if len(self.hist_distance) > 0:
                 self.hist_distance[0] = distance
@@ -254,12 +259,25 @@ def _update_raw_distance(self, reading_is_new=True) -> float:
             # modify in-place.
         return distance
 
-    def set_ref_power(self, value: float):
-        """Set a new reference power from the parent device and immediately update distance."""
+    def set_ref_power(self, value: float) -> float | None:
+        """
+        Set a new reference power and return the resulting distance.
+
+        Typically called from the parent device when either the user changes the calibration
+        of ref_power for a device, or when a metadevice takes on a new source device, and
+        propagates its own ref_power to our parent.
+
+        Note that it is unlikely to return None as its only returning the raw, not filtered
+        distance = the exception being uninitialised entries.
+        """
         # When the user updates the ref_power we want to reflect that change immediately,
         # and not subject it to the normal smoothing algo.
-        self.ref_power = value
-        return self._update_raw_distance(False)
+        # But make sure it's actually different, in case it's just a metadevice propagating
+        # its own ref_power without need.
+        if value != self.ref_power:
+            self.ref_power = value
+            return self._update_raw_distance(False)
+        return self.rssi_distance_raw
 
     def calculate_data(self):
         """
diff --git a/custom_components/bermuda/coordinator.py b/custom_components/bermuda/coordinator.py
index 5f2c660..26d39e2 100644
--- a/custom_components/bermuda/coordinator.py
+++ b/custom_components/bermuda/coordinator.py
@@ -926,10 +926,12 @@ def update_metadevices(self):
         other initialisation.
         """
         # First seed the metadevice skeletons and set their latest beacon_source entries
-        # Private BLE Devices:
+        # Private BLE Devices. It will only do anything if the self._do_private_device_init
+        # flag is set.
         self.discover_private_ble_metadevices()
 
         # iBeacon devices should already have their metadevices created.
+        # FIXME: irk and ibeacons will fight over their relative ref_power too.
 
         for metadev in self.metadevices.values():
             # We Expect the first beacon source to be the current one.
@@ -945,8 +947,24 @@ def update_metadevices(self):
                 # Map the source device's scanner list into ours
                 metadev.scanners = source_device.scanners
 
-                # Set the source device's ref_power from our own
-                source_device.set_ref_power(metadev.ref_power)
+                # Set the source device's ref_power from our own. This will cause
+                # the source device and all its scanner entries to update their
+                # distance measurements. This won't affect Area wins though, because
+                # they are "relative", not absolute.
+
+                # FIXME: This has two potential bugs:
+                # - if multiple metadevices share a source, they will
+                #   "fight" over their preferred ref_power, if different.
+                # - The non-meta device (if tracked) will receive distances
+                #   based on the meta device's ref_power.
+                # - The non-meta device if tracked will have its own ref_power ignored.
+                #
+                # None of these are terribly awful, but worth fixing.
+
+                # Note we are setting the ref_power on the source_device, not the
+                # individual scanner entries (it will propagate to them though)
+                if source_device.ref_power != metadev.ref_power:
+                    source_device.set_ref_power(metadev.ref_power)
 
                 # anything that isn't already set to something interesting, overwrite
                 # it with the new device's data.