I see more and more of them on the 718, You think there is any downforce added? I also noticed the GT4 front bumpers are being installed as well. Your thoughts?
You see more and more of them on Euro cars (and Asian cars, particularly in China, where the 718 is selling well) where such over-the-top decorative nonsense is considered a status symbol far more than it is in North America. For instance, in the first image, the car's also got rocker panels that end in tiny vertical winglets below the intakes. WTF?
Also, I'm going to assume that none of these are first-hand sightings and are captures from the internet. The marketing for this stuff online is omnipresent -- and the reality is the 'take rate' for these bolt-on baubles typically numbers in the single digits unless the company is well established. Even then, any proper Porschephile (IOW, someone who appreciates the car as a car, not the car as a status symbol) wouldn't be caught dead with a "GT4" wing on a non-GT4, just as any Bimmerphile wouldn't be caught dead in a car with ///M badging that wasn't an actual ///M car.
YMMV, but this stuff makes me shake my head. It's your car -- but this phenomenon is not
a phenomenon -- and, as @Porsche2018
notes, these add-ons are often downright dangerous at speed.