Since skirts were banned, F1 has been using vortices to separate high and low pressure areas at the edge of the floorpan. I really want to believe mercedes and audi are that clever, but can't seem to find a vortex generator in that style online
While the dimples seem to be a dead end, vortices under the car aren't. Sealing the floor of the car without killing ground clearance is huge for a street car and should improve the efficiency of the undertray if you didn't go too overboard
I would go for something along what ferrari did with the 488 because it's simple to make. 6 is overboard and performance minded, but one for each side could be used to fence the skirt area and duct some of the engine bay air
How the Ferrari 488GTB Makes the Air Its Ally