Based on some very superficial research there appears to be 3 software/MMS stacks.
There's some (dated) discussion here but the easiest way to check the state of MMS might be to update to the latest software and test with your carrier. p-boot could potentially be a good way to quickly test for stability, your network, and carrier compatibility.
At one point I was tracking developments with MMS but became pre-occupied with some other things, so unfortunately I can't help you more right now. However I will look into this during my free time for major Canadian carriers, and will even be able to do some testing with T-Mobile when I visit Las Vegas for a tradeshow in late Feburary. If I encounter unexpected issues will do write up in a forum post or my blog, and let you know in case you're still interested. But working MMS, along with along with Anbox (so people can run Android apps like instant messaging and banking apps on their PinePhone) will go a long way to helping people who just want to get stuff done, and not wrestle with random issues and bugs that everyone would prefer to take for granted.