It's not just R&D , for example the completely self driving thing would need a lot of compute or at least support of some kind from the cloud, that's a lot of money tesla has to provide for that feature every month it's not a one and done thing.
The higher acceleration probably kills the battery way sooner which is also a higher cost for tesla.
While I'm sure the self driving features require continual updates that cost them significant money to develop and deliver, I have some doubts that there would be much realtime compute based on a car's sensors being performed on their servers, as that would likely be unreliable, so it doesn't seem likely that enabling the feature on an individual car would directly cost them all that much. Of course, their reasoning may be that there are significant R&D costs involved, and charging a lesser fee to everyone would just drive up the minimum cost for those who don't necessarily want it. And there's also the likelihood that they might want to limit how many vehicles have access to the feature for liability reasons. If a car ends up crashing in self-driving mode, they are likely to face lawsuits, and part of the pricey self-driving fee may go toward paying for that. If everyone had access to the feature, there would likely be significantly more lawsuits, but not a proportionate amount of additional profit coming in from the feature to pay for them.
The acceleration boost could have similar liability concerns, though I agree that it could also shorten the life of components, potentially resulting in increased warranty claims, particularly when the expensive battery is covered to maintain at least 70% of its initial capacity for 8 years. But some things like giving all cars of a particular model heated seats and then locking the feature behind a $300 paywall seems a bit absurd.
One thing to consider about this "jailbreaking" though is that if Tesla detects it, that could be grounds for voiding a car's warranty. And that's probably something one wouldn't want to do when the cost of replacing the car's battery outside of warranty could be around $20,000 or more. And what happens if you are involved in an accident, and the insurance company determines that you made aftermarket modifications to your car's computer system? If things go wrong, one might regret trading in their warranty and potentially voiding their insurance coverage just to enable a feature that they probably didn't really need.