I also got a spontaneous reboot while plugged in and in USBMS mode. It actually ended up in YKNR screen but a power button reset cured it. But it might not have been related to the font hack.
Incidentally, I used your script to override Futura because the thin font used throughout the UI is hard for me to read. Works without apparent problems so far. and yes, the Default button did restore it. Then I overrode Palatino so now I have an extra custom font to use when the mood strikes
The PW2 is finally useable! THANKS SO MUCH!!