Is there any way to have attached a Switchback Seat AND still have both Cruiser seats available?Updated 3 days ago

Well, sort of.  

For this purpose, we'd recommend a 4-seat Cruiser XL and the Switchback Adapter for Cruiser. This would provide seating capacity of 3 (2 on one bench of the Cruiser XL and 1 in the Switchback Seat).