> I have quite a few interactors where I have optional (i.e. nilable) params, and I find myself using something like this in #setup (V2 branch) quite a bit:

Yeah that's cool for defaults, but there are times where I want to make a param required. I guess kinda like Rail's strong_params `params.require(:foo)...`. And failing fast make it easier to reason about that code instead of providing a default.