time alignment is not the same as volume. Time alignment is usually only needed when you have an amp or multiple amps, and one has a delay. I didn't know you could even adjust that from left to right.
If your speakers are not angled and placed at the optimum location, I WOULD GUESS, you would be trying to make the DS louder. Can't you just do that with balance control? Never heard of gain adjustment controlling side to side. Gain adjustment is to amplify the signal.