I expect your comment in the Github-issue #709 about missing indexes is a direct consequence of your comments here. You named an obvious cause, the missing indexes for the table mlf2_akismet_rating in case of an upgrade. I found the issue myself and made a commit, that corrects the copy'n'paste error I made, for the pull request with the fixes of the upgrade script.

Hi Auge, once I noticed the missing indexes, I did add them manually. Unfortunately, adding these did not materially improve performance on base 20240308.1 code. I then proceeded to make my performance modifications with these indexes properly in place. Thank you for also catching this and creating the pull request for the correction.

Joe