> So, if I have three patches in the stack, and I want to merge the bottom two, I'd merge one, wait for tests to run on the other, merge the second vs. merge just those two in one step

As we have it designed currently, you would have to wait for CI to pass on the bottom two and then you can merge the bottom two in one step. The top of the stack would then get rebased, which will likely trigger another CI run.

Thanks for the callout - we'll update those docs to make it clear multiple PRs can be merged at once.