You want to feed the carbs earlier in the cycle and not wait till +5 or +6 to do so. Feeding carbs later in the cycle can reduce duration and cause numbers to zoom up faster - aggravating bounces. I would have fed some MC/HC at +3 itself when he dived to 68.
It is a tricky situation. Bounce clearing cycles have additional downward momentum and reductions earned in such cycles often fail. Which is why it's OK to use a little carbs earlier in the cycle to prevent a drop below 50/reduction. However, with cats who have hit a breakthrough dose and are racing down the dosing ladder, it might be like standing in front of a speeding train. They clearly want to head much lower in dosing. Jude was in that situation in February, where it took larger reductions and/or skips to get the cat safely to the dose it wants to be at. I'm not sure Noogi is in that situation - yet.
@Helen + Noogi, shall we see what he does today (Sunday)? I know you are sleep deprived and exhausted and more importantly, you are back at work tomorrow and cannot monitor as closely. I just don't want to rush reductions and have him get stuck in higher numbers again. Cats that are prone to glucose toxicity can see them as quickly as after a single failed reduction! Maybe all he needs is a little MC at +2 in active cycles to prevent that dive at +3/+4?