Might as well use Brave at that point if I'm tying my fate to Chromium, though I appreciate your confirmation that there's no non-Chromium option to prioritize over Firefox on Android.
Sounds like I'll stick with Firefox and consider it to be the primary non-Chromium recommendation for 74% of the world's smartphone users who aren't on Apple.
EDIT: have a look at ungoogled-chromium, I have it as a second browser on my Mac:
https://github.com/ungoogled-software/ungoogled-chromium