I was able to test all 5 mainboards, BLE connected and distance sensor working. The distance sensor i2c pullups are 0201's, so whether they reflowed correctly is the iffy part of the design. One weird thing, one mainboard gave a general error when trying to program. I noticed the JTAG was connecting and reading the chip info. I read the chip flash and saw it was all 0xff, like I'd expect. I erased it to see if erase worked, and viola, it now programs. But, what the farts, why did this one board do this and not the others? Why does erasing fix it? Must be a weird flash thing.