I may have tried one...or two
The tray on mine is riveted on. I cut the bottom of a can (tuna I think..just the right diameter) to make a platform for the mini alky burners I built. I suppose the fuel tray could be removed completely and the tablets placed directly on the bottom of the unit. I've not tried twig burning in it, so I don't know about the feet.
The pot is smaller than what I'd want for a primary cooker...about the same size as a GSI nesting cup for a Nalgene bottle. It's nice as a Brewkit setup though.
I found it performed better with the alky burners if I put a fan grill on top of the stove unit. The extra gap allowed the flames to draw around the pot and not blow out the sides.