Bottom line - you have to brake hard at the beginning of the braking zone and then ease off - as you are are easing off the brakes you have to downshift. You turn in at the turning point after all this is done and the car is balanced.
What I had been doing was the street braking thing - start of gradually and progressively press harder and release at the turning point. This caused the shifting issues.
If you brake hard at the beginning of the braking zone and then ease off and downshift as you are easing off then all will be well and the tranny will be just fine thank you!! As you probably know gear changes occur towards the half way point in the braking zone if you are going down one gear. If you need to go down 2 gears then one change occurs when there is 2/3 of the braking zone left and the second change occurs when there is about 1/3 of the braking zone left. This is also the point when you should be almost off the brakes to balance the car prior to the turning point otherwise you can understeer like most automative journalists
Hope that helps.