OK I just booked my first HP trip as a US Chairman--followed the instructions, asked the reservations agent to put me on the cue for upgrade at the 7 day window (currently 11 days out), he confirmed that he did.

I'll call back the day before the window opens and check again, and of course at 7 days.

Thank you for the heads up!

For what its worth, the Elite Desk at HP is very friendly and helpful!

I'll keep you all posted