I can safely say now that the freezing is low-memory based - left my 770 working all night on stand-by and found it working in the morning. I'm using software watchdog (which judging from dmesg is not working , because the OMAP one restarts the device too often.

You can minimize the restarts by limiting the number of running processes in Android. BTW if your adb disconnects often - probably was killed for memory After that you need to reconnect the cable, then kill the adb server and start it anew.