Over the years, I have noticed that quite a lot of people don't like reverse headstocks, but I love them. They really have a positive advantage over conventional headstocks that many people seem to overlook.
On a six inline conventional headstock, the top "e" is longer than the bottom "E". Longer strings require more tension to tune to pitch, so the top "e" is the highest tension. If you use a reverse headstock, the thinner strings are shorter, so require less tension, therefore making string bending easier, and chords are easier to hold down. Strat style guitars with reverse headstocks are definitely easier to play. I noticed this when I got hold of a Squier (Fender) Showmaster guitar some time ago (no, that isn't me in the video!). It is fitted as standard with a reverse headstock, and it is certainly easier to play than a Strat with the same gauge strings.
Now, let's take a look at shorter scale guitars. A 24 inch scale will obviously have lower string tension than a 25.5 inch scale if the same gauge strings are used. 9-42 on 25.5 is fine, but the same gauge on a 24 inch scale can cause rattles on the thicker strings because of the lower tension, so you would normally fit 10-46 gauge to compensate.
However, fitting a lefty neck means you could stay with 9-42 gauge, as, being longer, the thicker strings will be under higher tension, therefore there is less likelihood of them "flapping".
I can't think of any disadvantages of reverse headstocks, apart from some people not liking the way they look (I actually think they look pretty good)