I actually just created my first PR from a sapling repo now - not sure why it’s not documented, but you can push your local development branch to a remote server, and in the case of github, you even get the “it looks like you’ve just pushed a local branch, would you like to turn this branch into a PR?” prompt, and it appears indistinguishable from a branch created with the Git CLI.
The message generated with the hyperlink for creating a PR is actually done server-side, you can customize any git server to do this, more or less. So yes, it should behave approximately the same assuming you can just do the basic push interactions.
