Rose's got some good advice. Since you've got 4 covered compartments, I'd go ahead and use all of them.
So far it looks like Wrigley's lowest numbers seem to be between about +3 and +6. In your case, since he's alone all day, I'd probably try something like +2, +3, +4, and +5.
That concentrates the food in the first half of the cycle, which is the time most likely for most cats to go into low numbers. It puts the carbs there in the time in the cycle when Wrigley has been lowest so far.
If a cat is clearing a bounce though - bounces overrule the normal Lantus cycle. Wrigley appears to be almost done bouncing, however. He's high around shot time but the rest of the cycle he seems to be dropping into normal numbers and staying there. His body seems to be fairly used to normal numbers.
One observation to share with you: At 0.75u he had just 6 shots before he dropped into the 30's. At 0.5u he had 5 shots before getting into the 40's. My crystal ball isn't always right, but I would not expect him to stay longer than 5 shots at this dose before he repeats this pattern - so I would consider that when deciding what to do with the feeder. He's got 3 shots already at 0.25u.
I would suggest that if you have any reason to think he might drop into low numbers, feel free to put high carb food and the gravy into the feeder.