> By all means, write it. Just don't use it.

I'd say write it, probably don't use it, and don't share it unless it's substantially better than the alternative.

This way, you'll learn about it, but you'll more likely stay with something standard that everyone else is using, and you don't share yet another library that wastes others' time and your own (having to read about it, evaluate it, use it, and the migrate off of it when it's abandoned).