You read warnings in a lot of posts of the impaction risks of using sand or soil as a substrate. The juvenile reptile in particular, it seems, is in danger of ingesting substrate with its food.

One of the favourite foods of my Southern Angle Headed Dragons is earthworms. They eat some termites, crickets and woodies but the main part of their diet is moths and earthworms. These dragons are young adults and they are thriving.

When I breed them, will earthworms pose a risk to juveniles because of the soil in their bodies?

Comments: I doubt it! Worms wont eat stones or sand in soil so any minute amount of soil inside should be passed without any problems.
If in doubt you can always chop em up for juvies, give em a bit of a wash etc.