Isnt the +1 just an additional year?
I would just get the $600 BMW Ultimate care and have the dealer replace your brakes before your BMW ultimate care expires
Unfortunately it is not possible to "just have your dealer replace the brakes before the ultimate care expires" (unless the brakes are actually at a point when they need to be replaced by the car's computer").
New BMWs use Condition Based Service (CBS) which basically has basically the car check itself to determine what needs service and when. So, you dont get oil changes every 5k miles or 7k miles. You get oil changes either 1 per year, or when the car says it needs it (approximately 10k Miles I think).
Same goes with the brakes, you can only get those changed under warranty if they need to be changed under warranty, and its "unlikely" you would need new brakes inside of 3 years /36k Miles, unless you stomp on your brakes all the time constantly (some people drive with their feet resting on the brakes, which is dumb, but I have seen it).
Its much more likely that a person would need brakes somewhere in the 4 years 50k miles time frame (but not guarenteed). It depends again on how you brake. For example, its my thought that cars with regenerative braking (which slows the car down when you take your foot off the gas fairly aggressively), reduces wear on brakes simply because you dont need to brake as long, or as hard to achieve the same amount of braking as in a non regenerative braking car.