Less is Better
Your pads are track pads (although I don't have any familiarity with the brand) and you've got good fluid but you're still experiencing brake fade. I'm assuming your disks are still acceptably thick. You certainly appear to be a good candidate for a rotor size upgrade. You could also think about just a disc upgrade, like a floating hub with directional vanes. You might also benefit from doing some work on brake cooling ducting.-- Yes, brakes feel fine starting the day. Pedal is firm enough. After a few sessions or sometimes int the first session towards the end of the session, the pedal has a lot more travel and the car seems to be not stopping as fast. At this point I am pushing the pedal very hard to stop the car and it seems like the "ice mode" is kicking in. As in once I push the pedal hard enough, the car actually is decelerating slower. This happens especially going up the hill at Laguna Seca righ
While I doubt it will solve your issue, have you thought about stainless lines? The rubber lines will get more soft with hotter fluid and the brakes tend to feel a little squishy.
I'm curious why you chose to put a higher friction pad in the rear? Do you experience any rear bias when braking hard? I wonder if this is inducing the "ice mode" feeling that you're referring to. Ice mode pretty much feels like the pedal has gone completely hard.