SAR pilots might at least have reference material with them to decode the ground messages.

FAA pilot training does not include learning about SAR ground signals so the person flying the small airplane down low near the person in need of rescue is not required to know the signals. Chances are that in Alaska many pilots have a reference card but in the lower 48 - not likely.

The signals table is a good idea for those trained and proficient. But much like Morse code, it's only useful if both sides are trained and proficient. Nowadays US navaids don't always use Morse identifiers because Morse is now obscure.
Even for ham radio operators Morse is now not required learning.