Lol, can't flash it now.
Steps:
1. Created KBPv60-like layout at
http://www.tmk-kbd.com2. Downloaded unimap.hex.
3. Installed Flip with JRE included, launched it and connected to the keyboard.
4. Selected unimap (load HEX) and tried to start application but it fails with "Could not write to USB device"
It looks like the PCB enters bootloader mode for several seconds only, cause when the keyboard is responsive, Flip returns "Could not open USB device", then I press the button and able to open connection. After I select hex to flash and press "start application" it just returns that "Could not write to USB device" and keyboard is active again.
Unfortunatelly, dfu-programmer doesn't even start on my system now, so I'm stuck with Flip, unless it is possible to flash it with msys