I would say "code it yourself, if it doesn't significantly slow you down". There's definitely something to be said for minimizing your dependencies, but if you're spending weeks implementing things completely tangential to what you're trying to do, you made a wrong turn somewhere. It's all about picking your battles, and I think you can go too far in both directions.
I'm personally starting to take the view of "sharpen your tools". That is, I'm fine with taking dependencies where appropriate, but I'm starting to contribute fixes and improvements to them as a way to derisk them. I think that benefits everyone.
