I have a lot of dragons so feeding time is time consuming for me... lol
I take my dragons out when I feed them, or feed one dubia at a time on dish in the enclosure. Taking them out is easier. I let them pig out and when they start showing no interest or slowing down a lot, I stop. The smaller beardies, I feed periodically through out the day. I have a container I put my Dubias in that I feed through throughout the day. I have had waaay to many hide when I try feeding a bunch in a dish.
I did come up with a clever way to feed a baby. I had a shallow tupperware container, I would put it next to his baskspot and he could jump in and out of the container, and the dubia could no get out. MUCH easier since he ate so many little nymphs.