My latest incarnation, decided to build a circuit board, plus as USB hub controller plus an aftermarket dc-dc , working the speed back up, I have found the problem that is causing my high speed issues seems to be ground loops, I guess it is to be expected with so many random parts in play. seems to be on the USB side I guess the long cable to the raspi that has a ground too. looks neat but doesn't work as well as I had hoped. I actually had all these parts already for many projects in the past. Have a single clock with a fanout buffer to the others. Plus all the work involved for such little gain really it changed it from ROI (just for the BE) in 100 days to like 70 ad the price I paid for them, buy then may not even do that. I think the best plan is to use the 16 Mhz and the resistor change far cheaper and effective. If I could get them to go to 28 Mhz would be lie having 7 for the price of 3 might be OK but I don't think I'll make it. As a friend of mine said "your pushing the limits of man and machine"