I'm fairly sure they are genuine VW units, just made for the aisa market. I wouldn't say the quality is really any worse, if anything (and I'm being picky) I would have to say that the dials feel slightly more scratchy on rotation and the plastics on the rear perhaps aren't as good quality, but the outward appearance and operation seem spot on. LCD's are equally as sharp and bright, LED's all light up the same colour and brightness etc. I've since fitted a different, used unit from a MK7 GTi that I got cheap, but that's purely because I found out I'd been scammed on a VCDS cable and it wouldn't work properly with the AliExpress one, nothing to do with the panel, just the old version of cable I'd massively overpaid some d*ckhead for is a Europe version.
I can't comment on the operation of the clean air button I'm afraid, because I don't have that panel fitted at the minute. But from what I gather the clean air system reads the air quality status from a sensor on the outside of the pollen filter. What it does with that information I don't know, but what I do know is that when you get your panel you need to go into the coding with VCDS and turn off/deactivate the Air quality sensor and both the inside and outside condensation sensors, otherwise your Start-Stop won't work and it will run the compressor more than it shoud, as it assumes the windscreen could fog up so plays it safe. You should also change the panel from it's default LHD to RHD if you're in the UK or other countries where we drive on the left. Otherwise the primary temperature knob is the left one, so when you adjust the right it will try to move flaps that just aren't there and you'll need to press the 'sync' button again.
Dave.