Whoever your HCP sends your impression to should consider how the shape of your ear canal and ear lobe could be used to anchor the mold - you don’t necessarily have to have an external canal lock. With my ReSound silicone molds, they seem to have a notch that catches my crux helicis. They stay put all day long with all the eating, talking, yawning, etc., one can do. OTH, if there is nothing around the ear canal opening to anchor to, as with Raudrive’s mold, an external protrusion may be necessary.
My ear canals have more “waviness” or curvature to anchor the molds, too. So some folks due to genetic and developmental “kaleidoscopes” end up with more canal/ear lobe features to take advantage of in designing a mold.
Edit_Update: And picture of the mold inserted: Widex Evoke Custom Mold popping out - #6 by jim_lewis