Reasons for not using a learned signal when a key move using an EFC will do the same job:

1) The remote has room for more key moves than learned signals, so if you don't use key moves when you have a choice, you might not have room for learned signals when you don't have a choice.

2) RC5, RC6 and other protocols have toggle bits which often cause problems for learned signals.

3) Sometimes you get a bad but working learn of an ordinary signal and don't realize that the reason the device is slow to respond or picky about the aiming of the remote, is because the signal is imperfect.

How else (other than JP1): We have discussed how to define EFC based key moves and which protocols can/can't have them, in many threads here.