Is it crazy to run my XY motors over CANbus instead of a wire bundle?

I looked at doing almost exactly this on my 2.4 and talked myself out of it, mostly for a hardware reason that's easy to miss: the EBB42 runs its driver off a 24V input, and the monolith motors are meant to be pushed harder than that. Those motors want the higher bus voltage your mainboard gives them, and the little 2209 on the toolhead board just doesn't have the headroom. You'd be running your X and Y steppers at a fraction of what they're rated for, and with continuous XY moves the drivers would be working hard the whole print. On a toolhead the motors mostly sit idle between extrusions, so the board lives an easy life. A gantry motor is a different job entirely.

The Klipper side is honestly the easy part, four nodes just show up as four uuids and you point each stepper section at its own. I run my toolhead, an EBB on the bed probe, and a canbus filament sensor on my 0.2 and the config is boring, which is what you want. The annoying bit is flashing. Every firmware update means getting each node into canboot one at a time, and with four boards bolted to gantry corners that means pulling panels to hit reset buttons. Put the reset wires somewhere reachable before you close it up.

Update: good news on the config side, turns out four nodes being separate is just normal and I can point each stepper at its own, so that part is off my worry list. But the voltage concern from the first reply has me stuck, seems these small boards really do feed the drivers from a lower input. Follow-up: your flashing comment got cut off, what was going to be the annoying bit?