Hello, when the side brackets are all the way up, I can turn a 27" Asus monitor vertically, barely, but it works.

Think so I have 2×24 monitors mounted

That's not a problem I have an HP S340c (34") and a Philips 237E (23") mounted and I can turn the Philips upright just fine.

Yes, that's exactly how I use it.

I've just checked, so the shots don't rotate, you'll have to leave the portrait monitor mounted permanently on portrait.

Hello, the mounting itself is probably not a problem, but the bracket is only intended for monitors up to 32". It could well be that you are then limited in the adjustment possibilities because the larger monitor touches the centre pole.