It's been easy. I've always thought their hardware was stupidly overpriced and that their software was made for children.
I looked into UBPorts and some other rare OS's but IIRC I didn't find anything that supports B13 CDMA which is the only band that matters if you live in rural 'Merica. So I just use android pones with unlockable bootloaders and that's the best I can do.
If I had my way, my cell phone would be an 8" or 9" linux laptop, but I think such tech doesn't exist.