It shows next to my name that way though no?
I remember someone doing that and it looked like a third name?
Discussion
Like if that's the case I don't care about it THAT much. If rather get into a conversation with a person at that point like Hermione "it's Nos-nehhhhhhv-its not Nos-knee-vets"
If it's implemented it should be a long press just it opens simple input field like "reactions" to set custom pronunciation. But it's not necessary to, personally I don't care.