P210 differences training in Europe presumably is not too different to a SET Class Rating course, which would include required manoeuvres for an SEP plus all the other differences of the type. If N-reg, also 14 CFR 61.31 (g) high altitude sign off and complex type sign off 61.31 (e). EASA differences training can be carried out freelance but the spirit of the legislation is for a well structured syllabus.
An SET class rating has five days of ground school and a week or so of flying training plus a check ride.
I own 2 P210s so more than happy to help you out on type specific training.
Could also make sure your aircraft is performing as per book(engine handling and pressurisation)
Feel free to PM me
Espen
