TL;DR
Arithmetic Combinators should, when freshly placed, be configured to multiply by one to reduce the clicks necessary to make it work as a diode, as this is both a common usage and because the current default settings are never relevant.What?
Currently, when placing a fresh Arithmetic Combinator, it is configured to multiply nothing by zero and output it on nothing.A common usage of ACs is to act as a diode - pass through all signals and isolate the input and output circuit network.
To do this, both the input signal must be set, the constant value must be increased to one (which requires multiple clicks and use of the keyboard), and the output signal must be set.
It would make the process slightly less annoying if the constant value was set to one by default instead. Then, you'd just need to set the signal you want to pass through.
(If the input and output additionally were set to Each by default, a freshly placed AC would immediately act as a diode, which would be even nicer for this specific scenario - but I see how that would be a bit more opinionated than it probably should be.)