Not sarcasm at all. I think you might overestimate the time and effort needed for this. When you maintain a _personal_ fork with no users except yourself, you only ever need to change something when you encounter a bug or need a new feature.

E.g. I have personal forks of mosh and cmux, each took maybe 1 hour of my time total?

I found this article https://news.ycombinator.com/item?id=49156111 resonating with me, except I obviously don't do stuff like "nightly cron to sync with main", I just never touch the code unless it breaks or I want a new feature.