Yep, the rollover is a bulkhead fitting, so it should be in there.
From what I've seen the rollover valves don't always work that great on a side flop, so you may want to run the vent lines similar to U4 cars if you don't want to spill gas on a flop.
126.96.36.199.6 Fuel vent lines must have a rollover check valve incorporated at the fuel cell, and must vent outside of occupants’ compartment, and be directed away from the engine and exhaust system.
188.8.131.52.7 Fuel vent line must use one of the following routings:
184.108.40.206.7.1 Fuel vent line must extend to the highest point of the roll cage nearest the fuel cell, across the width of the vehicle, and down to below the belly pan of the vehicle or 3” below the fuel cell, whichever is lower.
220.127.116.11.7.2 Fuel vent line must loop above the fuel cell to a point that is 4” above the top of the fuel cell. From there it shall be wrapped one full loop around the outside of the fuel cell near the top of the fuel cell and then be routed down to a point 3” below the lowest point of the fuel cell.
We flopped the Wag during a race and had never done either of the vent routing setups explained and we had fuel draining out of the cell until we cut a zip tie and moved it to the high side. (even though we had a roll over valve) Beyond the safety concern, it took us about 20 minutes until we had help to right the vehicle, and we didn't want to lose that much fuel since we are cheap asses.
The "3 and down" type routing do help gas spills since the vent will be higher than the tank in any orientation.
I copied the rule about having the vent away from exhaust because I figured that although it's common sense that you don't want gas vapors near hot exhaust, it was worth repeating.