Project level precompile caching?

Every time I activate . a project it seems that a bunch of packages have to recompile. If I have multiple pull requests outstanding and a few branches of my own packages this can add up to a lot of time when switching between projects that don’t share the same package versions.

It seems that Pkg is designed with the flexibility to allow precompiling (and ultimately compiling) multiple versions of a package, is this just a case of not implemented yet?

There an issue about it: There is no fix in sight yet, one work-around is mentioned though