P.S. I removed the zram (compressed RAM) option in the fstab because the Nook Color has a crappy enough CPU as is, so it wont help with zram. Use a swap partition on SDcard if needed.
P.S.2. This ramdisk is from the most recent nightly build (Jan 11, 2015). It may or may not work with older CM11 builds.
It's attached here. It wont let me upload the file as is, so I renamed it to uRamDisk.7z; rename it back to uRamDisk. After that, follow these steps:
0. MAKE A BACKUP OF THE /boot PARTITION IN YOUR RECOVERY JUST IN CASE. If anything happens, restore the /boot partition's backup.
1. Mount /boot partition at /root (it's an unused mountpoint in Android)
adb root && adb shell
# mount -t vfat /dev/block/mmcblk0p1 /root
2. Change directory to /root, rename the original ramdisk
# cd /root && mv uRamDisk uRamdisk.orig
3. Copy over the new ramdisk
adb push uRamDisk /root/
4. Reboot and profit
The internal sdcard will now be seen as external. You no longer need to have an SD card inside to have many apps like Kodi (XBMC), Firefox, etc, asking for external SD.
If it doesn't work for you for some reason, remount the /boot partition again, and copy over the original uRamDisk ( # cp -f uRamDisk.orig uRamDisk ).
I used parts of this script to figure out how to mod the ramdisk: https://gist.github.com/aperezdc/6533546