Perhaps, depending on how you define “one”. But that “one” can be can be a dynamic implementation, which can itself be filled in with the true, static, implementation somewhere else.
In any case, there can be no fundamental issue with higher order effects in Bluefin. If effectful can support them, Bluefin can support them. I just don’t see the point yet (because I don’t understand what they are or why they’re needed).
Perhaps the Hefty paper will explain it. I’ll take a look. Thanks for the link.