This problem isn't specific to cases where you are rebasing "again and again". Just needing to do a single rebase (e.g. prior to opening a PR) for a stacked feature is enough to need a solution.
And, as others have pointed out, the modern solution is `--update-refs`, so there's no need for complicated workflows any more anyway.
If you mean rebasing as each PR in the stack is merged, most Git platforms have the ability to do that automatically.
No, I mean small chunks that are actually merged instead of having a stack of them floating around.
A rebase before a merge can always happen, of course. But there are not stacked commits then it is just a standard rebase of your small chunk and that's it. And this will also have a shorter life than a stack so rebases will be rarer and simpler.