As from next August ALL IR holders must renew their ratings with the PBN qualification. When I contacted my old airline to ask for a letter saying that I'd already managed to find the ground in various Boeings so could probably manage it in my Piper I was told not to bother as the CAA had demanded that the whole pilot workforce be re-examined over their winter training!
As you say, there is a tendency for schools to push people into training but if you mug up on the excellent publication provided free by PPL I/R and the CAA CAP773 document regarding PBN in GA then you should be OK to simply answer questions and self declare previous experience.
As for the IMC rating (Sorry, I'm too old to rename it) then as far as I know nothings been decided but don't expect much in the way of mercy from either EASA or the CAA as this is obviously the hot new topic to 'ensure future safety'.....namely the new bone for the dog to chew on.