Insurers
Thats why with the FAA system, there is "An Insurance Mandated training Requirement"
This would also incorporate the high altitude endorsement dependant upon your training provider.
Under EASA, then the reference doc is FCL.700 and FCL.710
1 A single license endorsement for the Piper PA-46-310P (Malibu), the PA-46-350P (Malibu Mirage), and the PA-46-500TP (Malibu Meridian) aircraft has been
determined by the JAA.
2 Differences training which is not further specified, between the PA-46-310P (Malibu)/PA-46-350P (Malibu Mirage) and the PA-46-500TP (Malibu Meridian) aircraft
has been established by the JAA.
3 The Piper PA-46-500TP (Malibu Meridian) and the Jetprop LLC Piper PA-46 (Jetprop DLX) aircraft have been evaluated by EASA as variants requiring
familiarization training.
4 Difference levels for training, checking, and currency for the PA-46R-350T (Malibu Matrix) have not been evaluated and must be determined by the competent
Authority.