488 Brake problem? Or nothing to worry about?

Got a '17 488 GTB, picked it up in June (11k miles) and put 3,000 miles on it (not tracked). First exotic, so I could be worrying over nothing, but would appreciate your thoughts on possible brake issues.

MAJOR SYMPTOM:

- Braking hard from high speed, it has happened to me around twice that the brake pedal has gone 'hard' - a small amount of travel, then it will not depress any further despite applying maximum force - and stopping power is considerably diminished. This is NOT a regular occurrence, but then again I rarely brake hard from high speeds - maybe it would happen regularly if I did. Was a bit of a scare when I found myself hurtling toward a twisty off-ramp WAY faster than intended.

MINOR SYMPTOM:

- Brake squeal / hiss at low speeds. Function is fine. No big deal, I figured. Not unusual for CCs. Even some reviews mention it in passing without citing it as a defect.

POSSIBLE CAUSES (from researching other threads):

- Brakes were cold when applied at high speed. I was driving for 1hr+ on the highway, and moderating my speed mainly by lifting off the gas, not braking. Solution is simply to get some heat into them before smashing them from 100mp/h+.

- Glazed brake pads / brakes not bedded in properly by the original owner.

- Brake booster valve vacuum leak.

OTHER INFO:

- In normal city driving, the brakes work fine (despite the squeal).

- In spirited driving on twisty roads, where I am accelerating hard and braking hard constantly, I have not experienced the 'wooden pedal' sensation - the brakes work as expected.

- The car is due for service in January. I can ask them to flush the brake fluid / check the booster valve.

MY QUESTIONS...

1. Even though the car now has 14,000 miles, would it be of any use to do a (belated) bedding in procedure? I would assume it's way too late if the discs are actually glazed, but no harm in a second opinion...

Now, the big one...

2. The car is under full-cover warranty... For another 16 days. I can renew until the end of 2020. Service is not due until late January '21. I wasn't planning on paying the $6k to extend the warranty (not to open that can of worms here). Do you think, given the information set out above, that I should reconsider? Wouldn't want to cheap out on the $6k warranty in December and then be hit with a $20k brake replacement in January.

 

Yes, I should have mentioned - I'm out of the country until after the warranty expires... Annoying, unavoidable, short notice travel.

 

Cheers. This is what I assumed at the time. I wasn't sufficiently worried to take it to the dealer even though it was under warranty. Now my warranty's up for renewal, the incident just popped back into my mind and I thought I'd run it by some experienced owners for a second opinion. Unless there was a chorus of "That should NEVER happen", I didn't plan to take any further action.