It definitely isn't off by a factor of 3, I've tested the Zalman with known loads it is reasonable indicative even at low wattages.
The UPS isn't to improve efficiency just saying it is hooked up via that now - I'm using a DIY modified Eaton 3S Mini - I put quite a bit of time and testing into this setup including modifying the UPS with an ATTiny85 controller and writing custom software for it - part of which has been measuring the power draw under various different circumstances to make sure the UPS was suitable:
Definitely is strong word. There is no way that system is pulling two watts from the wall, especially with that box of tricks sat in between.
Why did you pick protected ICR cells BTW? To drop the management system?