Having a large part of your team be unable to reproduce bugs is a significant development issue

But I just said, they are free and able to use development builds, regardless of geographical location. As far as I know, the OS is exactly the same, just has certain things disabled depending on region (for example you can breifly see the iPhone mirroring in the EU the first time, before it disapears).

Firefox has struggled to get the sliver of market share they have today. I highly doubt that there are that many people like you and me who crave a real Firefox engine on iOS.

Why bother with any of it then? If it's hopeless and not enough people want it, why even bother?