I'm designing a PCB where I need to have two possible USB 2.0 connectors (and hence 2 sets of diff pairs) connect to a single USB 2.0 port on an MCU. Only a single connector would be used at any given time. What can I do to improve the signal quality? I've heard of redrivers/retimers but can these be used in this scenario to get around the effects of reflections due to the stub I would be introducing? If so, how many would I need and where would I add them?
This would always be implemented using a switch IC rather than just a junction; with that, there'd be no stub line, no need for redriving.
Many silicon manufacturers do offer such ICs, many even explicitly specified for USB2 signaling. Check e.g. TI.com's selection of USB 2.0 switches. Or Maxim's. Or NXP's. Or ON Semi's (show "ALL" instead of 50, search for USB). Or Analog Device's. Or intersil's (now Renesas). Or ROHM's.