That paper seems to suggest it for a triple balanced mixer, but not double balanced, unless I have missed it. With a double balanced mixer I would always expect the output to be the IF pins, even if the output is higher than the RF/LO. You need to be careful of the frequencies that the mixer is designed for. Some can be a bit narrow and generally the IF frequency specification is lower than the RF/IF in the specifications.
Maybe ask on the RF forum there will be some experts on such things there.
Keith.