NOTICE: Unfortunately, after confirming with some tests, it is possible to switch voices between GENDER swaps, but it is not possible to switch voices between RACE swaps with Glamourer. I'll be keeping an eye out with Sebastina for any updates, as I've seen is them mention they are waiting for a Glamourer patch that is upcoming. They are unsure if there is anything on the agenda to fix this. If you do not use Glamourer and instead use any cosmetic mods to change the appearance to appear as a different race, then it should not be an issue (i.e. making a female Miqo'te that is a male Viera canonically by having femboy features and Viera ears from body or gear mods)
A voice mod that switches Female Viera voices to the Male Viera 7 voice.
For anyone who has a character that switches genders, can't be bothered to Fantasia to change their voice or have a RP character who changes their voice.
KEEP IN MIND: If you switch voices between races and genders that are different from your character model, they may not match the lipsync and actions ingame. Sorry, nothing that can really be done about that
I plan to add more combinations eventually, but I only really plan to do them if there's any demand for any specific combinations. If you'd like to make a request, I made a server just for that: https://discord.gg/dy84Fz4Pgt