https://skysmith.com/category/cessna-skymaster/
In the above-referenced article, the broker makes a statement near the end "almost all pressurized aircraft will require annual school by the insurance company. Does not matter if it’s a Pressurized Skymaster or a Cessna 421".
The article discusses a low-time pilot trying to get coverage on a P337. I'm sure sim school would be required for such a newly minted pilot, but many of us "old dogs" have many thousands of hours in pressurized aircraft.
For those Skymaster owners with pressurization, do you agree with the broker's statement? Have you been required to attend annual training in order to gain or maintain your coverage?