I think the optimal time to upgrade something is just after the majority, so bugs have been filed, but the maintainer is still interested.
miniblog.
Related Posts
One big challenge of open source is that the number of users (and bug reports) is entirely independent of the number of maintainers. Both users and maintainer capacity can fluctuate wildly.
The vast majority of libraries have a single maintainer. Even if you weight by downloads, roughly half of downloaded libraries have a single maintainer too.
Wonderful post from the lead LLVM maintainer reflecting on how the project is run, the design issues in LLVM today, and opportunities to make it better:
