hey hey, just wanted to follow up with hchromia issue, so now i've fully investigated- it's not an issue per se.
When making heterochromia, you need to make a mesh from scratch because there's no heterochromia option yet in game and the downside to this is that you're having to use a texture space for other things so it will conflict with something.
I put mine over the "neck/choker" place instead of "pendant/necklace" as they're both the perfect size for an eye, so anything that uses the choker texture space will conflict.
I'm happy to change the texture space but there's not many options, saying that the options would be -
left & right bracelet space
glasses space
hat space
Please let me know if you'd prefer the texture space to be changed and what to, remember that whatever we change it to will mean it conflicts with that thing.