It reminds me of a lot of previous discussions about “task ports”. I wish I could find one with a more detailed response than this one.
The idea of ports is like asynchronous messages in Erlang. It is possible to create synchronous messages in Erlang, but that goes against the core design goals of having processes be independent of failure elsewhere. It would be odd to spend tons of effort to do this in Erlang.
I think these are all reiterations of wanting a traditional FFI in Elm. I understand that people want that, but as I say again and again, if we have a traditional FFI, we start getting direct ports of JS libraries. If that sounds nice, ReasonML and PureScript are both going to be nicer for that. You can go see if you like the results. Is their ecosystem better in your opinion? Maybe those languages are a better fit for your personal preferences or your particular needs?
So if you are not going for a way around kernel code stuff, I don’t really get why something more than Murphy’s advice is needed.