Is there a reason why we cannot export a tuple struct or tuple to the JS side?

#[napi]
pub fn plus_100(input: u32) -> (u32, u32) {
  (input, input)
}

#[napi]
pub struct X(u32, u32);

#[napi]
pub fn plus_200(input: u32) -> X {
  X(input, input)
}

In the first case, the macro complains:

the trait bound `(u32, u32): NapiRaw` is not satisfied
required because of the requirements on the impl of `napi::bindgen_prelude::ToNapiValue` for `(u32, u32)`

In the second case, the macros don't complain, but on the JS side, I get a X object with no properties...

On the JS side I would be expecting a heterogeneous array of some sort.