I am so unreasonably thrilled with this.
Buried in a Reddit thread I found a guy who trained a voice model with Majel Barrett clips, and he shared a link to it.
To actually use the model, I had to make an account at the place, then open this link again, then there was some "claim" button to get the model into my account. It was a little klunky, but you'll get through it.
The tool is free to use for a while, there's a character countdown. I don't know what the costs are afterwards.
The model is not perfect, but it's pretty, pretty, pretty OK. I whipped up this water leak alert sound, pasting in a classic TNG alert noise at the beginning. I can't embed an MP3 in this forum directly, hopefully this sharing link will work.
For consistency I guess I will try to get good renders of key words like "warning" and re-use them in the editing phase.
If anyone's into this too please share your creations! And if anyone's into audio editing and knows how to polish up the voice, please share some tips. It has kind of a room reverb on it, obvious on headphones but not so much on a speaker. It would be great to tone that down.
(Now I REALLY need a way to play sounds without the darn Google Home Mini bloop at the beginning.)