If I create a commit A and B in a repository and I open a pull request in Kallithea for these commits. Then (assuming the review repository and its fork are in sync) I will only see these commits in my pull request and reviewing it is a piece of cake. Now while the review is ongoing, if I continue to work on top of my previous two commits and create a commit C. Then when I push this commit to Kallithea and start a review, also commit A & B are included. Although these are already under review in a different pull request.
It would be nice that the changesets that are already in another pull request could be ignored (for example a checkbox to exclude them or ...)