I'm surprised something like this wasn't done sooner, and also haven't read the proposal [0] in enough detail to tell if this will lead to more data affecting the anonymity of users. Should be fine though, since it's tied user-to-service and not stored anywhere.

I'm wondering how much this will decrease load on the service being proxied vs the nodes themselves though, I assume it'll have more benefit to services since access is spread out between multiple nodes.

[0]: https://gitlab.torproject.org/tpo/core/torspec/-/blob/main/p...