I sought advice on this site last year, before buying a short-scale bass guitar: What are the disadvantages of buying a short-scale bass guitar
I've found the short-scale bass a wonderful instrument to practice, learn and perform on. One of my concerns was that if I was handed a full-scale bass, my skills wouldn't transfer.
I've found that it's fine. I probably wouldn't attempt anything at the more challenging end of my repertoire on a full-length bass (I have small hands anyway) but most things are fine. It's actually great to practice without having to stretch too far; then when I move to a larger instrument it's just a matter of stretching a big further.
All of this will apply to a 7/8 scale guitar.
I think it's worth practising with a variety of guitars; I have a steel-strung acoustic, a nylon-strung classical, and an electric, and each has a different scale length and neck width. It means that you'll be able to adapt if you find yourself at a party and someone hands you a guitar.
On the other hand, there's something to be said for playing the more difficult pieces on an instrument you know intimately.