Gold dig for me, but whatever. Same question was on Arcadia Gitter (https://gitter.im/arcadia-unity/Arcadia) and issue (https://github.com/arcadia-unity/Arcadia/issues/388). Arcadia seems to be abandoned. Original authors (Tims Gardner https://twitter.com/timsgardner and Ramsey Nasser https://twitter.com/ra) seems to not have enough time for maintaining it. But it still works, at least in Unity 2021.3 LTS - I've checked is some time ago. In 2022.1 there are errors, which prevents from running play mode. But you can always make fork of repo, fix it and share here. I was even thinking about it, but also running short on time by now.

Have you thought about talking about Arcadia Godot instead of arcadia unity @ekhart? @selfsame is still around and does some stuff on the godot version.

I know selfsame from Arcadia Unity. He shared his solution for Godot first there. I've done also game in Godot, but it was some time ago.