[MC5C]

The overall length of the strings (above the nut and below the bridge) affects what Ken Parker (and I) call dynamic tension. That is the change in tension as the string is fretted or bent. Long overall length strings feel softer when playing than strings that have no after-length (like a strat with locking nut, for example) but very short overall length strings bend notes more effectively. It's a subtle difference, but it's there. I am currently building a new neck for one of my archtops that is more of an electric guitar with a 6 on a side tuner setup like Parker's, to see what happens...

Sympathetic resonance from the afterlength is a thing with archtops. I quite like it, the more noise the better for me, and that echo/reverb is what I associate with an acoustic archtop. It's really common to see strips of felt wound through the strings to deaden the afterlength, and Herb Ellis used a string damper just below the nut to dampen all open strings. He never played open strings, I guess, and didn't want them to resonate at all.