Circuitoids are a generalization of a category where each morphisms has an arbitrary (possibly infinite) number of arguments. Two morphisms are not required to have the same number of arguments.
See this manuscript where I first define circuitoids.
I haven’t (yet) defined some notion of associativity for circuitoids. This may be a topic of our future research.
My attempt to generalize some things I research in terms of circuitoids was a blind valley.
I’ll better analyze every case separately, not to try to generalize all in one formula about circuitoids. Such generalization has little benefit.
I think I wrote that short article about circuitoids in vain.