Here's another update: I recently was able to recompile ALXR and change the color that gets turned to passthrough from black to green! Here are new instructions to download the modified APK as well as use the background color changer plugin:
1. Install and run the ALVR server code on your PC that you're running VaM on
https://github.com/alvr-org/ALVR/releases/download/v18.2.3/ALVR_Installer_v18.2.3.exe
2. Sideload the attached ALXR apk to your Oculus Quest 2 -- this uses green for passthrough instead of black (also attached to this post if you can't download):
3. Make sure you've downloaded the camera background color changer plugin:
https://hub.virtamate.com/resources/camera-background-color.24185/download
4. On your PC, launch VaM
5. Once you're in VaM, use the Left Menu + Right B button combination.
6. Now add the background color changer plugin as a Scene plugin and set it to a shade of green that you'd like to use for passthrough.
This will fill in the green areas with passthrough and make the model look like she's in your room. You can also try Left Menu + Right A button which will blend both and make her appear like a ghost.
Note: You may need to adjust the exact shade of green you're using to prevent the model from having too much of a green outline. Unfortunately some green outline is unavoidable due to using this method but it can almost eliminated. Have fun!