A bit like the differences training for different types of twin. I have yet to hear of a MEP examiner to refuse to test someone in a type they haven't flown before.
Tesco - It's not only "types", it's also variants/models. I'd flown Seneca 1's, 3's and 5's. Then came time to fly a Seneca 2.
Asked the school to send me a Pilots Information Manual and company checklists (UPS, at my expense) two weeks before I arrived.
Then postponed the first test I was scheduled to do and flew with a senior instructor in the Seneca 2 before going anywhere near it as P1. It
does happen (occassionally). Granted - I didn't pay for the flight - but didn't log it as command either. Also did some "area famil" before venturing out in the wild unknown.
Another "tick in a box" on the checklist of life - you've now "heard of an examiner that refused to test someone in a type they hadn't flown before".