Eggs / embryos will not fall out as embedded in a big brain like mass that kind looks like tapioca jelly. Hatched sac-fry are likely to stay piled up near where father keeps his head and belly while ventilating brood. In my experience the sac-fry can move about well enough to stay as a group where they need to be. Dad key to that. Without dad like in a raceway, sac-fry might pile up but do not try to stay anywhere in particular. Fry will be the ones that come out as school.
Lip could prevent straggler sac-fry from coming out.
