Using capacitor on a Mo and Krill who is burrowed will remove the resistance buffs, but it will also shift their hitbox. I did not test it extensively but it seems to move their burrowed hitbox a bit above the ground.
I've tested this too and the interaction is pretty weird. It acts like it canceled burrow by pulling them out of the ground but it doesn't always cancel. Weird item interaction. I'm not really a fan of the buff removing aspect of Capacitor myself. It's pretty upsetting to be saved by a clutch cube just to get un-cubed by an obvious upgrade to a gun farming item.