looks like someone decided to solve this.
apparently there are alpha release repos available now that do not contain branch names
https://deb.torproject.org/torproject.org/dists/:
[DIR] tor-experimental-bookworm/ 2021-12-20 22:21 - [DIR] tor-experimental-bullseye/ 2021-12-20 22:21 - [DIR] tor-experimental-buster/ 2021-12-20 22:21 - [DIR] tor-experimental-focal/ 2021-12-20 22:21 - [...]
thank you! nusenu