gotta say that back panel would be critically important, the tight fit of the USB 3.0 cable coupled with a constant need to remove the nvme drive on the rear has resulted in the breakage of several USB pins, ruining the value of the motherboard.
How many times did you have to remove the nvme drive? Just curious, because I actually didn't had a need for that in my system so far nor did I have an option to put it into another system.
And yeah, I know that USB 3.0 20-pin connector is terrible, but that's a standard at this point and we are eagerly waiting for the 3.1 gen 2 header (that ASUS connector) become a standard for mITX. At some point we were considering just using the 2.0 version because of that in Sentry but people wanted 3.0 on the front and that's reasonable to have high speed connection up front for data transfers.