I just experienced a flakey random no boot failure.. looks like this msb is slightly slower ramp-up 5v on startup..and causing my QT PY to stumble on power up..I doubled up the 10 ohm 5v input resistor .. 2 x 10 =5 ohms.. so far this seems to be enuff to make it stable start up.. I'll keep checking it today.. might have to go to 1 ohm ..hope not..