I'm extremely pleased to hear that you are "still alive" as that's mandatory to enjoying life
I will most certainly PM you with any Gremlins I find or what I perceive to be so.
It seem to me the best procedure is to simplify the .cwp by removing all MIDI and none needed audio clips and saving this as a striped down version of the project in a different folder before conversion.
I will test further as I have only converted 3 projects but I have notice that some buss's are converted into a Reaper folder with child tracks and some are interpreted as independent tracks, all of theses buss's have tracks routed to them so not sure what significant difference there is to make this so.
When all said and done this is a remarkable achievement... well done! and thank you for sharing.👍