There should not be any change in tension; that's a function of the vibrating length of the string, all else equal, and the afterlength is not part of the sounding length of the string.
It could make some difference in intonation, providing the string slides easily through the nut slot. As you depress the string the tension rises, and the pitch shifts up a bit. The amount the tension rises depends on the material and coonstruction of the string, the distance you push it down, and how long the string is, so the afterlength can come in to that. In theory a longer afterlength would reduce the tension change and give better intonation, or, at least, reduce the needed compensation at the bridge.
Making the vibrating length of the lower strings longer can help, but it's a little roundabout. Back in the Olde Days before overspun strings the onlly way to get a decent low note was to use a long string, and you saw archlutes that were six feet long to get the low drones to work. Then somebody came up with the idea of adding mass to the string to drop the pitch by winding wire around it. When properly done this works pretty well, and the string makers have had a long time to figure out how to get it right. Still, it is uaully better to use the longest string you can for low notes.
An electric guitar maker, Ralph Novax, was thin=ing about another aspect of string behavior, the 'zip tone', when he came up with the idea of 'fannned frets'. He toook out a patent and a trade mark, before somebody pointed out to him that they'd made orpharions like that a few hundred years back. His idea worked in the way he wanted, and it has been copied ever since, although it's often called 'multi-scale' in defference to his trademark. It turns out that the string on the Classical guitar that has a 'zip tone' problem is usually the D string, but changing the after length won't help with that.
In short, it strikes me as a solution looking for a problem.