I agree wholeheartedly, and I think the main blocker is the way multiple dispatch is resolved on some base module (usually Base) instead of being resolved by the caller.
the general outline , along with some overly emotional correspondences (mainly on my side) can be found in
this thread:
I also wrote a small POC using macro that generate a generated function … the added indirection gave me enough flexibility to prove that this is possible.
If there is interest I will “patch” the POC to work on julia version 1.0