Neat! We started working on something similar, using LD_PRELOAD. After setting some env variables we'd see a commit's files layered at some path, on top of artifacts saved for this commit. The goal is to run jobs that expect to access both git files and build artifacts, while avoid duplication of storage. FUSE would be better but users don't have enough permissions.
Libs that use C# but nobody wants to try building on Linux, Windows binaries we get as-is from outside the organization, C++ code relying on MVSC non-standardness, C code relying on a custom toolchain that can't be ported...
I'll give it a try, MCP apps are full of promises but protocols are so unstable that I wouldn't want to write the boiler plate myself.