True fact "my cat's numbers are all over the place" or equivalent, is the most common phrase on this forum. Welcome - you have joined many of us who have felt the same frustrations you are now feeling.
Bouncing is perfectly normal for cats, and drives us caregivers crazy. There is only so much you can do to help him slow down the bounces, which are caused by either steep drops in numbers, or getting to numbers he's not used to. To reduce the steep drops, you have to figure out at what point in the cycle he dose those drops, then feed him some food a half hour before hand, so he has fresh carbs on board before the drop starts. More detail here:
Using Food to Manipulate the Curve Note, that post was written by someone using Tight Regulation as a dosing method, so you'd have to switch mentions of 50 (2.8) with 90(5.0) or whatever you are using for your reduction point. Which I think is 70 as per your signature.
The second way to get him used to lower numbers is to try to keep him safely at a dose that sees lower numbers than he's used to. Note, you dropped the dose from 4.0 to 3.75 units with him going to 74, which is not below your reduction point.
