I have little time to investigate what's the difference between partition label and partition name (since msdos disks obviously do support labels, so wtf!?) together with what changed in Debian that suddenly made this an issue.
So I've just taken a blunt approach and made the installer check if labels are supported, before trying to populate the UI with them.
See here:
https://gitlab.com/Cofi/trios-installer/commit/90310e899dab429d5c62a95a10e92898225ae434So the biggest potential "issue" if I got it wrong is that the labels won't show in the UI when they are actually supported.
If I get some time later today I'll go through the install fully (by mistake I booted into a VM I need/cannot format the disk), and burn the ISO on the flash and check it out on the metal... Right now it doesn't get stuck on the partition list screen.
With that said, until I get to it, I suggest testing in a VM only, just in case

Also, as usual, the fix is in the "testing" branch, so make sure you build the installer from it