Mismatch in Set / SetOp causes (undesireable?) cartesian Coeffect Kind

[buggymcbugfix]

none : Int [{} : Set X]
none = [42]

weak : forall {a : Type} . a [{} : SetOp X] -> ()
weak [_] = ()

good3 : ()
good3 = weak none

This type checks despitenone being Set instead of SetOp.