Hey CookieBadger, i just bought your asset, hoping it would work for me. I am using an M1 Mac with Godot 4.1.1 mono-build. After installing .NET 7 and .NET 6 and your addon i got some errors while activating your addon.
I followed instruction from another C#-addon: Go to "Project -> Tools -> C# -> Create C# Solution". After i have done that i rebuild my project, restarted Godot and did your install instructions again. Then i got it working. After writing this i found out you have to hit the build-button. Maybe this does the same, i just pressed the play-button thinking this also builds your project. But i guess it does not, nevermind...
I played a bit with Assetplacer and it is such a joy to work with this. I think this will be essential for my 3D-Level-Design and i would be grateful if you can support this for a while ;) If i am more advanced with my project i will post screenshots in the other thread!