It depends wholly on where the frames have come from, and by that I mean the factory and not the country.
I’ve no problem buying a frame sourced from anywhere, provided that it’s durable and does what it says on the box. It’s easy to judge the geometry, but durability is something that you have to take on trust. If the frame dies the week after and the seller denies all knowledge of you, you’re pretty much screwed.
That would be at the forefront of my mind when buying an unbranded frame from the net…