Thanks for reading :) Broken down by key idea:

- Allowing actions/setup-go users to specify a cache key prefix so that they can have more than one golang CI job, each with its own cache: this is 100% worth upstreaming. I believe there are existing requests and PRs about this. Up to you guys to implement however you see fit.

- Allowing "always update the cache": also a good idea to enable as an option, very important for non-open-source teams that are trying to maximize cache hit rate.

- Allowing "trim the cache": if you're going to allow always updating the cache, probably a good idea.

But the "always update" and "trim" cache changes combine to have a lot of risks regarding cache poisoning that might be bad for open source projects. Lukas may have a different opinion or more to say on this front.