(I too use Firefox, even on Android.)

I just don't like this idea that downstream maintainers need to be saved from themselves by limiting the options upstream provides them.

Downstream are not end users, which I agree should only get tested builds. They're professionals too, and they can be trusted to pick the configurations they want to build, evaluate how much more testing they need, and cut out configurations from their support matrix if they don't have the resources to support them.

Also, this idea that a professional project wouldn't offer untested combinations of settings to other professionals is why people follow up asking about Linux. A quick search tells me it's got ~19,000 Kconfig options[1].

[1]: https://dl.acm.org/doi/fullHtml/10.1145/3646548.3676548