borders-plus-plus: Inconsistent offset when using negative border size

[bodby]

When general:border_size = -2 and I have two borders configured as follows:

borders-plus-plus {
  add_borders=2
  border_size_1=1
  border_size_2=1
  col.border_1=rgba(efefff25)
  col.border_2=rgba(00000060)
  natural_rounding=true
}

The border on the left doesn't line up with the window. The right side looks fine, but left should go an extra pixel to the left.

I am on a 4K display and haven't noticed this on 2K.

[bodby]

This may be a problem with hyprscroller or with gaps_out or gaps_in. When I have another window to the left, the problem disappears. And when there are no windows on either side, the weird alignment happens on both sides.

Doesn't seem like hyprscroller's fault though.

[bodby]

... mostly. It still appears at the bottom of windows unless I have a window underneath that too.

It also appears if I resize windows precisely enough, maybe because the border boundaries get "truncated" so they are sometimes one pixel inset.

Plus I have fractional scaling which might be the main issue.

[bodby]

tl;dr borders don't align with windows perfectly all the time with a negative border size when using fractional scaling.