Yep, I know of some beardie breeders who claim they give silkworms as the sole feeder insect for very young hatchlings and claim they get a great headstart from this diet cf with woodies or crickets.
BSF maggots are near impossible to buy as feeder insects here in Australia and I expect if they were available commercially these would the feeder of choice.
I gave George and Mildred (BTS), then Puff and Rex ,and more recently Peppa and Toothless, small silkworms as one their 3 daily insect meal when very young (up to 4 months old) and as they and the worms grew, it become medium silkworms as one of their two daily insect meals up to about 6 months old at which point I ran out of silkworms.
This is how I raise them :
viewtopic.php?f=76&t=222193
I tend to give a mixture of staple high quality live insects to my lizards when they are young and growing fast. Silkworms are great as a feeder insect - I essentially left the worms on a bit of fresh mulberry leaf in their feeder bowls - the worms don't move fast of far.