Hi Yanni,
As I expected, the trouble arose in areas where I was creating instance-based magritte descriptions. In my PRComponent subclasses I was already creating prototype instance, it seems. I tried a few things to fix things up, but could not get everything to work right yet.
I'm not going to complete the port until it becomes clear what the timeline is for adopting the new code, because I don't want to maintain two code streams.