Yep, acceleration, mileage, speed, all software locked. Mainly to keep from damaging the vehicle.
Want to have fun? Hook the motor instantaneously to the battery. Sure, great acceleration, up until things melt.
As well as I can remember, they had to replace some of the buss bars in the Model S, because they would melt with the speed increases.
Tesla's speed increases generally come from a lot of review of the dynamics of all of the attached systems and then testing them to higher forces. It's a big trade-off between short term increases in performance and longevity of parts that has to be decided. Basically it comes down to "If we optimize this, will the MTBF of all of the pieces still stay within an acceptable range"
Artificially software limiting, like reducing battery capacity is another thing. It's a trick used by manufacturers when features are often more expensive NOT to implement. After all, companies are in it for the money.
