Für VP, Turbo, EFIS, etc. braucht man kein Difference-Training sondern "nur" Familiarization. Was das ist, kann man in GM1 FCL.710 nachlesen:

Es wird immer falscher. Beim Instant-Googeln zur Vortäuschung nicht vorhandenen Wissens bitte auch Ergebnisse 2 und 3 beachten...

Aircraft within the same class rating which are separated by a horizontal line in the tables require differences training, whereas those aircraft which are contained in the same box require familiarisation training when transitioning from one aircraft to another (3). As an example, SEP (land) aircraft with variable pitch propeller and SEP (land) aircraft with retractable undercarriage require differences training (unless credits have been established through the OSD), whereas two different SEP (land) aircraft, both with cabin pressurisation require familiarisation training.

...

(a) Differences training requires the acquisition of additional knowledge and training on an appropriate training device or the aircraft.

https://www.easa.europa.eu/download/typerating-lists/Explanatory%20Notes%20EASA%20T_R_List.pdf