I use the Harmony 890. I picked up a couple of refurbished units for about $100 each for two of my rooms. I have been very happy with them. The only issue I have is that in our living room with tall ceilings, if the remote is blocked in a certain way I get double hits, no amount of tweaking of the settings seem to be able to stop it.
The way I believe the UFO setup works is that when you press a button to generate the IR signal a small amount of RF is released by the remote and then it will send that signal to the UFO unit. So yes, I believe both the IR and the RF will work. Then you would have to make sure that you fully cover the IR receiver on each unit, which is sometime easier said than done.