Suggested

'Dirty air' Effect

Tricky one. With DRS dirty air is about good as it is or could even be stronger, especially at some tracks, but loosing power faster with distance (aka a faster car has less trouble opening an one second gap but an about equally fast or even faster car has not as much problems staying in an area of about one second behind, unlike Monaco now).

But I'd also like to try races closer to touring cars, less finicky and fragile aerodynamic open wheel series or F1 in the past. No or much less DRS, much less dirty air effect that allows (at least slightly faster) cars to get into an usable slipstream effect.

Also what might be worth considering would be making the wing value affecting dirty air strength, so on tracks like Monaco or in rain with already high perfect setups the effect is automatically reduced but also managers could set higher values above perfect which slows them down somewhat but makes their cars less sensitive to dirty air through more brute wing downforce (at the cost of more drag). Difficult choice, but perhaps your car just happens to have ample more Acceleration than you competition in that rain race.