[Mark Postle]

JDT,

Quite a few potential ways you may want to alter the training but as a start I would definitely encourage you to do an AeT drift test on the inclined treadmill.  I commonly use this method for my coached mountain oriented athletes with good results and as you theorize here you can definitely see a bit different results than flat track based test.  I have even occasionally done both tread and stair stepper test to compare.  Once you have a better handle on your AeT you can make some more informed decisions about training intensities!