I have flashed my DevKit to version 3 of the core. At first, I was able to see the boot screen and interrupt the auto-boot, but for some reason, connecting my 1541 drive, and rebooting, I am unable to see the boot screen and it auto-loads the maze program. I disconnected the 1541 drive and tried again, but still have the same problem. The 1541 worked just fine before flashing to r3 of the COR.
Also, not sure if that red light was there before, but maybe that's a sign that something isn't right?
Here's a video: