I also ran the start.bat file from QuickCure3-with-flasher and got this:

QuickCure3 v0.2 by kunix
payload comment:
HWID&SWVR; MOV R8,R12

Initializing USB...
hwid = 972
swvr = 420
name = nⁿvi 13xx Series Software Version 4.20

Initializing USB once again...
sending the payload...
all done
now the device should enter the mass storage mode
Press any key to continue . . .

Should I flash and RGN at this point or is it just done? A power off and power on of the device still has garmin boot loop.