UDP2-12AP is garbage
I've purchased their KVM switch UDP2-12AP, I fell for their advertisement, and some youtubers seemed happy with their product.
It's a massive disappointment: the audio has a constant ringing noise, and I'm using their own audio cables (which btw they only send you 2, when you need 4 to connect everything). I contacted customer support and they advised I buy ferrite beads. But if this is a known issue, why wouldn't you include ferrite beads with your cables? But of course the ferrite beads didn't help at all, so that was another waste of time and money.
Secondly, their DDM USB ports only support basic mouses and keyboards. But they advertise it as "best kvm switch for gaming". And in their showcase video they use a corsair k70, but they don't mention that it's in BIOS mode, which means it's a basic keyboard with fancy backlighting. no macros or extra buttons or features are supported.
Thirdly, you can use the regular USB ports, but your peripherals will occasionally fail to boot up. you need to disconnect and reconnect them on every other boot.
And the cherry on top, after all these issues, I decided to return the switch, and they don't even cover the return cost. So I've basically wasted a bunch of time and money, just to test their overpriced garbage and confirm they've lied in their advertisement.
Avoid this company at all costs!