This is more of a function of battery chemistry on the S/X - the Model 3 does not have the same power restriction under load.
I am a Model 3 owner, I assure you it will reduce power after a time. No need to take my word for it though you can find plenty of autobahn demo videos showing it. It's not terrible but it is a thing and it's "worse" with track mode.
Numerous "sporty" car reviews also mention this fact. It's just the way it is. Not an impact to most drivers. Absolutely critical to someone who loves the track.
That is not to say that the Model 3 is entirely unlimited in its power delivery. But a 2018 S/X will go into a low-power mode before you can even finish one lap on the ring and the Model 3 will not. The stock Model 3 Performance brakes will overheat however.
I’ve watched several videos where Bjørn Nyland pushes his 3P to top speed for sustain periods and does not see any power limiting. He shows the same driving on a Model S which gets power limited.
A cursory Google search finds several Tesla forum threads showing people with 3P not being power limited on the track.
I am also a Model 3 owner, and I’ve never seen it reduce power, but I’ve never driven it faster than 110mph for a few minutes, and don’t take it on the track.
The main issue I’ve read about 3P is that the brakes overheat. It needs carbon ceramics on the track.
It is universally acknowledged that power delivery on the Model 3 is better than S/X.
Presumably it would be a suicide run to match the Taycan, which to my understanding would involve modifications and not be eligible for the same category.
Either it was an idle boast, or we're about to see the launch of the 21700 Model S.
The most pronounced new feature is the ability to charge at up to 200kW on the new V3 superchargers. M3 can do up to 250kW and non-raven S/X can only do in the low 100s.