@athompson thank you for that script you uploaded. Does it work with NBI's created with AutocasperNBI? The reason I ask is due to when I manually update them, I have to rename Netboot.dmg to Netboot.sparseimage, but I didn't see those commands in your script (didn't look very hard though).
The netboot.dmg is what it should be looking for, but when I dbl click the DMG to copy the new C.Imaging.app, an error pops up that the DMG is Read Only. So I rename to a .sparseimage, copy the file, then rename back to .dmg.