One thing to note on second rodeos is that you need to be much more aggressive with dosing than the first time. It is much harder to get a cat into remission the second time (first hand experience over here

). So I would go with the increase as soon as you can, and then not stay at one dose for very long unless the numbers require it. 3-6 cycles and then increase again. You might also consider getting the U100's so you can feel comfortable with measuring smaller increases.
Also, any kibble can be too much kibble. BG increases have been measured on even just a few pieces - folks sometimes use them when their cat is going too low too fast. I'm wondering if we can help you find a food for your other kitty that might be safer for both of them? The SO is for urinary issues, right?