I've had trouble sourcing the Adafruit APDS 9960, but SparkFun has a slightly differently shaped board with the same sensor and wiring pinout. Here's their github repo with Eagle files. The Prospector case would need to be modified to hold the SparkFun board. I don't have a Fusion license and I think even this simple modification to the STEP file is beyond my skill with FreeCAD or Onshape.
If somebody with a Fusion license wanted to try that would be really appreciated.