That brings up an interesting point.
In Missouri, they also have a "License law." In Missouri, the C&R satisfies this rule, and then anyone with a C&R then fills out a form 1 or form 4 and can then own suppressors. (I don't know for sure if it applies to ALL Class II items, but I know it is used for SUPPRESSORS.)
I am un-aware of anyone in Michigan going through this process. I haven't heard of anyone doing so.
If you know of someone who has done so, it may be possible to do it in Michigan as well.
If that IS indeed the case, then it isn't without precedent.