I've noticed that my 360 will go into a standby mode after 3 or 4 hours, a mode not the same as the energy saver mode (I have that set at 72 hours). It dosn't seem to cause a problem and I never noticed any use of ink at all, indicating no cleaning cycle. Then after an overnight pause with the printer in standby I get a low ink warning. About 1/3 of one yellow ink stick had been used up while the other inks were just the same as the night before (I monitor the color ink closely because we are waiting on some new supplies to arive and have no color spares.)
Is there something at work here causing only one ink to be used up? Some sort of incipient problem? Temperatures look fine, check prints look fine when done. The printer is left on all night. I shouldn't be having this problem.
As a side note, as an interm solution I have scheduled one of the servers to send a color exercise print (just several horizontal lines of solid color - hair line wide in each color) ever 4 hours to keep the heads exercised. Hope it helps.