Thanks for all the input, and really glad I called to change.
It seems that the prior agent had not actually applied the FNC to the reservation. She had extended it a couple of days - the the date needed for the stay, but then not applied and took 70K x 2 for the two nights.
This agent cancelled that and booked the two nights using 70K points and FNC at TB. Also, she was able to book a combined reservation (FNC and points) in one reservation rather than two as I'd previously done. I always linked them for no issue, but a single reservation is better.
I really appreciate all of the insights about London hotels on this board. It has served us well on past stays and seems to have improved this upcoming stay.
Cheers.