NUnit fixture with non-matching constraint on fixture class is silently ignored

[v3.27.0.3]
Given code below, is there a way to have NCrunch warn me about BFoo is not matching the constraint or this purely due to NUnit technicalities?
(If I supply the 2 TypeArgs in same fixture no test is run on the fixture)

[img=https://i.imgur.com/YnAQATX.png]Code[/img]

Thanks.

Unfortunately this is all behind the NUnit abstraction. We try to avoid digging into this logic because when we do, it inhibits our ability to treat NUnit as a service that provides us with test identifiers and allows us to run them generically.