My strategy for that sort of thing was wrapping all the stuff in unsafe modules that exported safe API's. Just do some basic checks as function is called then messy stuff is handled in its own little file of scary code.
I was doing this in other languages way after you were dealing with Modula-2 on even older hardware. So, I'm curious as to how you and others then handled that problem? What were the tactics?
I was too young and too distracted by the world of being young to focus on it enough back then to truly sit down and do that. By the time I got my Modula 2 compiler I was 13 or 14 years old and then high school happened and about 3 or 4 years later I had a PC running (pre 1.0) Linux, so. I never had to truly deal with it.
The strong types did get in the way of interfacing with a lot of OS level stuff that wanted to deal in void pointers tho.