Question about determinism and atomicness.

A while ago I saw people were getting rapier to run atomicly inside bevy and spacetimedb and when they restarted their clients and server the physics synced back up. It looked like it was really efficient too. I think they tested it with millions of objects. Is something like this supported out of the box with avain? If not my second question is.. Is it possible? And if it's possible how hard would it be to do?