I'll answer this question myself, in case someone else wants to know the answer to this question and runs across this thread while searching:
I went ahead and ordered the 350 version of the PRL-V2 and tested it with my PC 690. The answer is that bit changes above the table are practical and easy with one offset wrench to hold the lower nut, and a standard straight wrench to tighten and loosen the upper collet nut.
So if bit changes above the table are important to you and you want to use a Porter-Cable 690 with this router lift, go ahead and do it. I bought my offset wrench from Woodcraft and it's a well-made piece of gear - actually better made than the OEM wrenches that came with the router.
Having said that, I might as well mention that I actually purchased a Porter-Cable 890 for the table, for a bit more horsepower and even easier bit changes. I'll sell the PC 690 with my old benchtop table.