I didn't put a brightness lock in SuperDim, because I didn't find the brightness lock in AdjBrightness to work very well.
By the way, I suspect that your Nook may well be waking up just fine, but with a brightness set to zero, so you can't see anything. :-) I don't know if you have any way of checking if that's what's happening. But if that really is what is happening, I think I can work around the problem in SuperDim.
That said, I am still a bit surprised the brightness lock works for you. Maybe it depends on the app? Can you try an experiment for me? Set the correct brightness in SuperDim, and exit SuperDim. Then, using either a terminal app or an adb shell, execute the following commands:
chmod 444 /sys/class/leds/lcd-backlight/brightness
(You'll probably get a root privileges prompt after the "su".) Then see if that locks in the brightness for you.