The omoplata can be turned into a sweep if uke attempts to top spin escape.
Tori, anticipating uke is going to top spin escape, controls the knee/leg uke places on their belly. Using the circular momentum of uke, tori pulls uke over their body, barrel rolling away from uke.
If successful, tori will be in a position that they can easily gain top position by either going chest to chest, re-rolling the omoplata, or back stepping to mount.