The second 5% bump wasn't a purchase. Tesla rolled them out in two different software updates at no cost.
As for OP's question, I purchased it last week for my 2020 LR AWD. I've driven both this and the performance, and while the performance is quicker, i don't regret the speed boost. I can't imagine going back, and like many others, I'd love if they gave us the option for the extra boost to get to 'stealth' levels in the future.
I'm not sure of the technicalities, but with
Wugz findings I'm hoping it's possible since he the rear motor peak power was technically reduced with this acceleration boost. I don't know how it would work in conjunction with the front motor, but in theory there should be some room left even with the 990 motor in the newer cars.