Unless you have an Airsource 3 with the corrugated hose that clicks apart, I assume you mean unscrewing the corrugated hose at the left shoulder.
I do something very similar (unscrew a dump valve) with my bcd, so no theoretical problem. Not as easy to open the dump valve on the Aqualungs because of their proprietary cover and thin plastic - easy to break.
So if you take off the connection at the shoulder, don't lose the thick rubber washer that seals the two parts. It's easy to get stuck in one half, forget that it's there, and then have it drop out while you're working the hose.
Second, it's also easy to cross-thread the plastic fittings, since they're fine. So be extra careful putting it back together.
Finally, there's sometimes a ?12-sided? boss that is on the fitting, that fits into a similarly shaped recess on the shoulder of your vest. If your connection has that, make sure the angle of your connector is exactly how you want it, or you'll have to unscrew and reposition it. And if the boss is not in the recess, you won't be able to screw it down fully.
But no, no problem with doing it this way. I agree - working thru the inflator fitting is slow and frustrating. Though do make sure to rinse that fitting well, too. It's the most failure prone pay of the bcd due to corrosion.