Steve, what do you think about trying to hold this dose for a while longer?
Usually, the kitties who have returned from the Falls once have to work harder to get back there a second time. We really want him to go back to the Falls, and we want to try to make that remission as strong as possible so he will hopefully never come back again. I would put Brutus more into the category of needing to surf in green (with a little low blue) for 7 days for a reduction, unless he drops too far below 40. If you were having to feed a lot over the cycle to keep him up, that would be a little different. When you reduced last night, his numbers went right back to blue, and when you raised it back up, he went green again. Looks like he needs this dose for a while longer to make the green more firmly established.
Another thing, have you tried Low Carb food to bring up the lower numbers now that he is on such a small dose? I know with Lucy, I would HC everything low just like I always had. At some point, Jill or Jojo came along and pointed out that there was now a LOT less insulin to overcome, and that LC might do the trick. I tried it and was surprised that it worked! Once I knew Lucy could surf the 40's on LC, that made me comfortable to hold doses longer. I knew that even if she went to the 40's, she could easily bring herself up with the food that was already sitting out for her. I was able to relax a lot, test less, and just let her surf. Next time he's dropping, maybe try LC and see what happens. If it doesn't work, you can always pull out the HC next.