Thanks for suggestion , now I know what to actually google for hardware, but the prices are indeed something. I will try to see if I can go the VM route (will ahve to pass through a thunderbolt lane to a VM) and debug it on that level, or if I start looking for rentals

This is killing me. I think I remember, either a kid on a project I worked with once was telling me about it, or I watched an EEV blog and he mentioned it like off hand. It was a high level USB analyzer with a BNC connection and a low level port so you could connect a logic analyzer and/or a scope and it would tell you the high level USB status. I know I'm never going to find it, but I was very reasonably priced IIRC

There are "beagle" usb analyzers.