Lisa -
You are correct -- with SLGS you hold the dose for a week unless your kitty tells you it's time for a decrease (i.e., numbers drop below 90). Since it's been a week and numbers are still not where you want them, it's time to increase at AMPS.
As far as nadirs, this was a very flat cycle. Your AMPS was your lowest point. Other than your AMPS, Prince's numbers ranged from 281 to 301 -- the entire range was less than a 20% variation. I would not get too stuck on where nadirs typically fall -- they can and do change. Cats like to be unpredictable!
I had the same reaction as Chris when I looks at your spreadsheet -- you test enough to consider TR. However, there can't be any dry food in Prince's diet.