In the specs published by Zoom they say the device is capable of recording 6 simultaneous tracks (the mic or whatever at the top, the inputs at the bottom, and a stereo mix of those sources). Checking the full manual, they state that recording the mix file when the inputs are set to 192kHz is not possible, but I'm not seeing anything about not being able to record 32 bit float from only one pair of inputs. And if the Zoom H2e can do that, well, I'd expect the H5Studio to do it!
As for the X6 only recording two channels in 32 bit float, looking rather quickly through the manual I can't see any reference to that limitation - the nearest thing is that 32 bit float is not available at all in 'podcast mode'. I have to say that I'm glad I haven't got an X6 as it seems very confusing to use, though perhaps that's my antiquity speaking...
Interesting that they took down that video. The video they should have taken down was the one for the humble H2e, where they show a group of musicians being recorded with the H2e placed in the centre of the group. And it's mono audio, which kind of completely undermines the point of the video. A couple of comments suggested they should take it down but it's still there. Anyway, back to the H5Studio...