When emitting code for comparison operators, the F# compiler already special-cases numeric types. I suggest that, when other value types have the appropriate operator, code is emitted to use it. I.e., the compiler should produce the equivalent of:

let inline (<=) (x: ^a when ^a: struct) (y: ^a) =
(^a: (static member (<=): ^a * ^a -> bool) (x, y))