This is great; I've been waiting for this to be picked up for a while. The only thing Prism now lacks is application-layer sandboxing for Java mods, whose importance was shown post-Fracturizer. Perhaps this is something that could be done with Nix too, with a runtime injection into the mods' prologues that interfaces with a shared coremod library. The principal issue with this approach would be JRE privilege escalation requirements. But this is putative, and I'm glad this project targets a few steps that would otherwise be preliminary.