The flap on the diffuser is HUGE since I don't know of any rule limiting it's size. Is this the next slotted diffuser???
Could there soon be a flap on this flap???
Anyway I can also show you the F-duct. Yes you read that right. This uses a fluid switch (like the FW F-duct) but is fed by slots in the diffuser/gearbox/diff area. The air exits a pair of holes in the endplates just under the rear wing surface. Of course it will only stall the outer section of the wing closest to the endplate but could eliminate the vortexes formed there.
There is also a slot just above the wing which feeds the same outlet as the F-duct. That (I think) will also create a vortex that would run under the wing and add DF. OK I'm not very sure about that last bit but I didn't post this stuff only to show off
Here's the slot above the wing:
It also does the job of the slots we normally see in the endplates.