What is the most optimal Erlang/Elixir you can think of regarding standardized effect systems for recording non-determinism, replaying and reversible computing? How comparable are performance numbers of Erlang/Elixir with Java and wasm?

I'd recommend asking the Elixir community about this as I didn't even understand your question. I am by no means a professional with Erlang/Elixir. I threw it out there because these language force you to think differently compared to common OOP languages.