Italian here, I don't really have utaforum or anything but if he has any socials/contacts I could reach out. I made several Italian recliste before so I can definitely help

Got sent this, I could lend a hand (I'm unfortunately very Italian)

To be really fair it's really good at separating them with context, I even took out dx and ax and it's perfectly fine at distinguishing them

Yeah, with DiffSinger there's no limit in those regards. I do suggest trying to stick to already established phoneme systems merely for a ustx intercompatibility thing, but if properly set up that shouldn't be an issue either

There's no limit, you can choose your own phonetic system. The only issue is the English phonemizer only supports arpabet, but I think you can set up replacements and/or you can make your own dictionary with scripts

Synthesis!!