How do you pay the rent building open source dev tools?

I'm currently building Nap, an open source test automation tool. I would describe it as a more advanced tool for developers and QA engineers who know a little about Javascript/YAML. I'd love to work on tools like this full-time, but right now I'm still working for a salary. My only opportunities to work on this project are doing time off or when my employer's needs happen to align with this tool.

So, I'm looking for ways to monetize and eventually "make the leap" into solopreneurship. I have a strong belief in open source, and I want to keep the tool free for anyone to use. I also don't want to introduce some official walled garden to try and rent-seek, since avoiding lock-in one of the reasons I built it in the first place. So, what other options do I have for monetization? I have thought about Patreon or Github Sponsors, but I am not even sure of the best route to market myself or this project.

Paid support is the obvious, low-effort solution here, I think, but is this tool even big enough to warrant that?