Thanks for saying so Parametric.
I use the "Elevenlabs" website to create these voices with, and I (sadly) agree entirely with you, in relation to all the other AI voices that I've personally heard as well. Small note though, that new accounts can't make these voice clones anymore, and now it's only a paid service to be able to produce these with new accounts.
However with that being said, they've added a new "Design your own voice", that has roughly the same quality level as the clips I provided, best I could tell from a "glance" at them.
These you can create as a free account, so I'd definitely give it a look if you're interested in potentially making your own voices as well.
In terms of alterations to the voice, there's a decent amount of "re-generations" involved in getting just the right emotional inflection on words, and generally alter the voice to sound roughly how you'd want it to sound (even with using voice clones like I do). I'm probably feeling compelled to splice several generations of the same text manually together, for roughly around 30% of it, to get it all sounding just right.
Innately, Elevenlabs only supports sliders for "Stability", and "Similarity/Clarity" to directly manipulate the overall voice with for each generation, however with that being said, there's several ways you can attempt to make the AI add a specific emotional inflection to the way it says things. Say if you wanted it to SHOUT something, then you could write it as "She shouted: "Insert Text to be shouted", or "She said sadly: "Insert text to be said with sad inflection". This doesn't always work, but has a high degree of working.
Generally the AI will try its best to add the emotional inflection to words that it thinks it should, but it's very hit and miss, and either takes some re-generations to randomly get, or prompts like the one described just above.
In relation to using Cat Taber to voice both people, I personally don't think that you'd ever think it's the same person speaking, from just listening to it (I've yet to hear anyone point this out to me, unless I've specifically told them which template I based the two voices on).
In relation to her work as Vette, I'll say that yes I agree that there's a lot of similarities, but after having listened to near all of her voice files many times over, I personally believe that for the most part of her performance there is actually a genuinly (subtle) difference, despite obviously having used her Mission VA work as a foundation for creating it.
Given that the AI only uses around 8 minutes of audio, I just picked the voice files where I felt it was most pronounced, to try and give it that "same but different feel" to the point of sounding like two similiar but completely different people from one another.
I also think that if someone wanted to make a K2 voiced Mission mod, that if you went and took all the files from Vette where she sounds the most like Mission for the template, that you'd end up with the perfect voice for "An older Mission" fitting for a K2 setting (lowkey a dream of mine in the back of my head, if I ever manage to fully realize my goals for this project).