Nearness to the bump stops on a Miata and this car could be quite different in what is acceptable.
To determine the best drop that enhances and not detracts from handling requires a bit more info, one is tire diameter.
On 225/45/15 Rival S on 9" wide wheels, as well as my RA1 race tires which are a bit shorter, the inner mount center of rotation is slightly higher than the middle of the ball joints which is close to perfect just as it was with the 24....whatever I forgot now diameter 205/45/17 Mich PS-3 AS tires I had for a bit which raised the car quite a bit yet filled the fender gap better. Suspension still optimized but the higher ride height effects the weight transfer quite a bit.
Note: I would have to cut apart the ball joints to get an exact center but with looking very carefully at them and having physically moved them in my hands I am sure I am very close, close enough, the car drives like it
The Rival S in stock tread depth is listed as being 23.1" in diameter but sitting on 9" wheels which gives me an effective close to .5" more tread width measure unloaded at street air pressures at 25.5", same specs and end results as the RA1 track tires in the same size and when on the ground will be smaller in actual diameter when driving and get smaller yet as they wear.
All that said up front I have a 1" gap from top of tire to fender opening, which have been rolled and pulled quite a bit so might not be the same stock now. It might not look as fast as tucked but handles immensely better when overly lowered, to me a different first letter would be appropriate to use
describing it, starting with an "."