Accu-tip and question

[Ken Jankura]

Hi list, 
  I'm still using my SAT II, waiting for SAT III,  and wondering what ser.#
SAT III has been shipped so far (patience is my forte).
   Here's a tip for us footswitch users that I don't remember seeing in the
discussion a few months ago. Turn the footswitch around 180 degrees and
rest your foot on the 'hinge' side. Lift your heel to note-step. Keeps it
from scooting around the floor. More relaxing for the leg.
   Here's another question- Mention was made a while back of the FAC values
for a particular piano changing over time. How is this possible? I've read
"The Calculating Technician", and I'm wondering what could change the math
used to calculate inharmonicity. String elongation/deformation? Rust? Alien
space rays?  Please keep in mind that I am not an engineer :-) so higher
math might elude me. Just trying to understand. Thanks 
  Ken Jankura
  Newburg, PA