I'm not very familiar with the use of these plugin-linked HW devices, but they seem to be poppung up everywhere.

Got a question- In practice how does someone control multiple of these devices? Say you got a dual channel Pre, 2 x mono comps and 2 x mono EQs (like this Bettermaker Pultec here).

That would be 5 x USB ports right? And these are directly connected to the computer by USB, right (so they don't connect through the interface)? So would someone need 5 USB computer post to be taken up on their computer to run the stereo channel strip signal chain I described?

If so then it seems that these companies are going to be competing for USB port access in a way that with new WAY more fiercely competitive than the competition for 19" or 500 Series rack space or interface IOs. USB port access is quite limited on most computers and often taken up by other necessary peripherals.