I’d say you are mostly correct. But I don’t know if I’d call them the winged portion of BOSS, they are 2 seperate sanctions that are owned/operated by one person.
A quick comparison of the 2 schedules looks like it’d be quite possible to run the entire schedule with both series with the exception of May 24. But they are allowed to drop one race per series. And the nights they are both at the same track would not be easy.