While working on the fix and realizing I might be on my own, I found myself wondering what Eloquence might be like if we combined Sam's logic with the Rust host of davidacm/NVDA-IBMTTS-Driver, just without the IBM specific plumming? What we get is lower RAM usage and, maybe it's just my ears, lower keypress delay. We still, for now, have the need to copy an executable onto secure screens, there are no interface changes in this version. But we cut RAM usage in half.
This is vibe coded, although I should hope it was done responsibly. If there are any issues, report them please. I am using this in production going forward and enjoying it. Again, thanks to all who have come before me, and I hope this is useful to someone besides me.