I at least push things as PRs when I find them. Heck, I just dug out some things from my dotfiles that have stagnated in the past 10+ years since I vendored them and submitted cleaner ways to implement them in the past week[0]. I can't really do much to get them *merged*, but I don't keep them secret… I also push hard[1] on upstreaming any patches we do at $DAYJOB to projects we use and have things that are upstreamable (not everything is).

[0] https://github.com/zsh-users/zsh-syntax-highlighting/pull...
[1] To the point where I ask for a PR link (or issue link if it is suspected we have a hackjob in place) before accepting a local bugfix.