If you want the drum to sit any lower, you've got to find a way to lower the attachment point between the carrier's hooks (the eyelet hooks, not j-hooks) and the drum's eyelets. There are a few possible ways to do it, but the option I'd probably try first is using straps & clips instead of solid hooks, like you'd find on XL carriers such as
this one.
If you've got some old carriers laying around, you may already have the parts you need. If not, one way to do this on the cheap is to use dog leashes for the straps. The end of most nylon dog leashes are pretty much identical to XL's straps & clips. Buy a couple of cheap leashes (preferably about 1" wide), cut off the last 6" or so with the clip, and burn a hole through the leash with a soldering iron to pass a bolt through. (Burning instead of cutting keeps the nylon from fraying and unraveling.)
As for comments on playing height... On a 32" bass, there isn't a whole lot of range for adjustment unless you've got a really tall person carrying the drum. It needs to be low enough to see the top of the person in front of you and hopefully high enough you don't kick the drum whenever you take a step.
WHS: Unlike snares & tenors, most of a bass drummer's carrier is hidden behind the drum. With that in mind, I wouldn't mind if one of my students sought out a better-fitting carrier if he was uncomfortable. I tend to be a bit of a stickler for detail when it comes to appearance, so I'd suggest looking for a carrier with similar-looking shoulder pieces so that you look as much like your linemates as possible. Most Randall May t-bar or tube carriers should look pretty similar to the Alumi-Vest from behind, assuming they've got the back support bar.