Personal preference.
I have both my aider and adjustable daisy on the locking biner in a two aider system. In moving, I clip a free biner to the piece (or bolt) and clip the locker/aider/daisy to the biner. Then I bounce, get on that aider, and then move the second locker/aider/daisy to the free biner. This keeps the two aiders vertically aligned and allows me to move either the left or right l/a/d to the next piece. I'll lock the biners at anchors at the end of pitches.
Other people use different systems.
That works for sure but why not save some wear and tear on your locker and get more reach for the next placement (you are higher above your piece if your aider is clipped into the top biner) by keeping the locker on your harness until you hit the belay? I think this would speed you up some and not have to deal with open gates.