Maintainers always seem to say you should file an issue before working on a PR. However, I find for features you really need, you should just fork the software yourself[0] and implement what you need, then put up a quick PR with your changes. The worst they can do is reject your changes, in which case...well, you're using your fork anyway.
[0] Github forks are lightweight, easy(ish) to keep up to date, and integrated into a lot of package managers.