Although it’s hard to remember specific bugs from three years ago, I personally never ask for an AAF from Pr. OMF actually works for me all the time as the format hasn’t been developed for over 20 years so it is robust.
Perhaps an XML from Pr with original media might work better but for me an OMF is rock solid. I think you might like version 18.1 Everything about the Fairlight page has improved enormously since version 16. Basically everything has improved on all the other pages too.
As fo extra tracks, I sometimes find editors just repeat the same tracks to make things louder. Half the job for me is cleaning up and deleting repeats, guide, ltc etc etc. So it might be the editor? Worth asking how many tracks they have clips on