I honestly should probably do a bit of reading first as I know nothing about footswitches, but the footswitch being a "binary control" does not exactly answer my question. But going with what you say, is there any reason I would not be able to send binary voltage to that port? Basically the idea is I could send a gate from eurorack to the footswitch.
The reason I ask is because the ETC honestly looks seriously badass. It is amazing looking, but when I perform live, I am completely computer and midi free. It would be absolutely incredible if I could somehow add a bit of control from eurorack. The LZX stuff is a bit more of a commitment than I am looking for.