I know you don’t want to talk about these ones but they are funny. Seems a gimmick rather than there being any benefit? I’ve got a Dillinger Escape Plan live 7" from the dimitri days which does this and its just a faff 
Notice!
Due to the intricacies of the mastering of this 7", all songs may not be playable on all turntables.
Track A1 begins like a normal 7".
Track A2 begins slightly after the starting point for track A1.
Track B1 begins like a normal 7" but ends on a locked groove in the middle of the vinyl.
Track B2 plays from the inside out and ends in the locked groove in the middle of the vinyl.