I started out on an i76 Slingshot with a windsurf fuselage from my windfoil setup. Aspect Ratio: 2.
As you say, low Aspect are draggier, so they make gliding round a gybe harder. You need to have the power on for longer, then get it back on sooner after you change your hands. For beginner gybers, this makes it more difficult compared to a mid/high AR
A long fuselage makes it very stable in pitch, but the downside is you need a lot of force to pump it. Low Aspect should also be easier to ride, as they have less of a change in lift vs AoA,so shouldn't be as sensitive to ride. A more advanced rider might find that annoying though.
Having less wingspan will always make a foil turn better. Ultimately, there is always going to be a trade-off between glide/drag, and the ability to turn.
There's a reason that these two have completely different wing shapes, the one on the left needs to be highly maneuverable, the one on the right needs to glide as efficiently as possible:

There is another difficulty with making a wingspan huge - it will break more easily. With aircraft, you might end up needing to reinforce the wing so much, it becomes very heavy and nullifies any decrease in drag.
Personally, I like my current foils with an AR of about 6 (Sabfoil 799+899), but the conditions you ride in make a big difference as to what foil shape you might want to use.