It would be kind of useful to have the default value, but that can be kind of worked around by doing a "make similar" which carries forward the checksum value. So that would be kinda useful.
What would be super cool would just have LEARN train as many aspects as possible, Sysex string, midi min max, display min max (default same as midi min max), number of bytes in value.
I think this is one of those all or nothing things, as it would be so cool when fully implemented. So well worth waiting for as a full feature.
I did a layout with 36 sysex control knobs on, and believe me, it took hours to tweak and perfect, when I recking this feature would have let me do it in about ten minutes...dump all the knobs on the page, then rename the labels, then just keep clicking LEARN. Also, not having to click APPLY after a LEARN would make it very slick to just move from one control to the next LEARN'ing each control...slick and efficient.