This is not directly about code or any concrete technical-only reason to create an RFC (?).
I think that the important_packages idea is good, but every time the evolution of the compiler may break or flaky some package test, like when a symbol is deprecated or removed, the core devs should NOT spend time and efforts fixing some random user projects to make the Nim CI pass, also sometimes the pull requests have to wait on the user responses and merges (that user may not be even actively coding anymore), because when all this in-between process happens the Nim pull request that was ready to merge now may be out of sync with devel by several commits, I understand the "good intention" and all, but I think is critical for the core devs to focus on fixing the Nim compiler, to use all available possible manpower and developer-time to fix Nim. Being listed in the important_packages should be like a way to "highlight and honor" a Nim project. If that package is not actively fast moving to keep up with the evolution of Nim compiler anymore, then it should be removed from the important_packages (or commented out at least), projects should move forward by its own traction, and not implicitly stealing developer-time from the Nim compiler. Projects can always setup their own stricter CI anyway. TLDR if a project in important_packages breaks a test in devel, then it should be removed from important_packages, not "try to PR it".