Too bad
@bean discontinued the 1590A Imp V2.
Here's a gutshot from the interwebs, ie not mine:
With my Imp PCB and a Runtime Error PCB (both MBP 1590A boards of identical width) they will not fit side by side in a 1590N1, however...
I could fit the aforementioned boards in a 1590N1 if I put the circuit boards on edge. With 2mm thick double-sided foam sticky tape, I could mount them to the sides and the foam tape would push the PCBs far enough away from the walls for the lid to fit on (regular double-sided sticky tape would NOT work because the PCBs would interfere with the lid's lip).
Oriented normally, the Imp and Runtime Error fit together in a 1590B3 perfectly — with enough space that the control's of the PCBs won't be too close or interfere with each other.
So, I'd prefer a single PCB designed with two Klones on it to fit either a B3 or a BB in portrait mode (though landscape mode would offer better stomper separation).
While a two Klones-PCB in a single N1 might fit, as mentioned by Robert already it'd be a tight fit, but do you really want two footswitches on an N1? Personally, I'm moving away from such cramped stompage.