Your understanding was correct about my potential desire to erase all key assignments in one sweep for one device. If this can be accomplished with the steps you outlined, then I'm satisfied. I don't want to have to erase each key individually, and I want the ability to refresh the original key assignments when a new setup code is entered after erasing the old keys.

Do you have any suggestions about the power on problem with the STB other than manually covering the transmitter?

The exact way I added key assignments to 10047 (assume you had a typo) was simply to test it with the direct EFC entry (tap P then enter the 5 digits), and if the test worked, then I used 994 commands to assign the EFC to the desired key. Also, if a key was already assigned in another device, I did a key copy to the new device. Once or twice I used the learning feature from the STB remote. This all seems like standard procedure to me. I don't know how to do these things any advanced way. I simply used the off-the-shelf setup codes that applied to my devices, and then supplemented the buttons with new EFCs that I discovered or was given.