I believe that this is the same problem, does Mozilla leverage safari? why does it not return its own user-agent?

Hi Paul van Dyk, all browsers for iOS are built on top of Safari due to Apple restrictions on third party browser engines.

The convention for Safari on iPad now appears to be to mimic a desktop computer rather than revealing itself to be a mobile device (although I'm sure there are other tells that developers can discover).

Firefox for iOS 25.0 changed to hardcoding the Safari UA. I know users have endured a lot of websites reporting their browser was out-of-date because the version numbering on iOS is much lower than on desktops. That seems to be the motivation for using the Safari UA for now so sites do not need to be fixed to recognize FxiOS is its own thing:

https://github.com/mozilla-mobile/firefox-ios/pull/6468

It's not clear how soon that might be tweaked again.

Is it important that sites recognize the browser as Firefox for iOS?

Yes, it's quite important, for my specific case I need the user agent to render relevant data and modify which views I return to the end-user. We retrieve the page based from an HTTP req header's user agent.

This is all done server-side to avoid users loading unnecessary data. But due to the lack of this user-agent using firefox, I always need to assume that it might be firefox and instead I have to do extra device detection at run time, which means my pages/data for firefox on iOS is loaded for all my other users (chrome, edge, safari, etc. etc..)

Based on your original question, the two that look hard to distinguish are Firefox on iPad and Safari on iPad, since Firefox uses Safari's user agent string. Does something bad happen if you treat Firefox on iPad as Safari on iPad?