Sharing packages between projects (global cache)

As someone who works on several projects at a time, I find that the Library/PackageCache folder gets big very quickly for each project (over 1GB), most of which is just duplicated and takes up around 66% of the project disc space. I get that each project uses version X of package Y but 99% of the time its the same (latest) version.

Rather than each project having its own package copy, can we have a global package cache (which contains multiple versions if needed of each package) with each project having pointers to the version it requires instead? This would save a ton of disc space.