Kris explained the process perfectly. Looking at your spreadsheet, he seems to drop well with 1.5 on a red preshot (like he did for this morning's number.) msom that looks like a good dose for that level. I'd suggest that less insulin would be needed for a 246 - just like you did this morning. He is higher mid cycle today, but one unit worked well for the 247 a few days ago. He might drop again for pmps, or it might just be a little flatter and higher cycle.
So, although it feels like you are just giving insulin, I'd say you are doing a great job. He has gotten some nice preshot numbers and the ss has more blues and yellows than before.
The hard part, for me at least, is the odd numbers. Like your 330 today. He could have dropped early; he could be bouncing a little from a lower number overnight, or he could have seen a squirrel

. Unless you are getting a curve, it is sometimes hard to figure out what one number in the cycle means. So you just look at the general pattern and give doses that make sense based on his previous levels. And some never become very predictable - look at Teasel's spreadsheet. I think you are doing fine. If you want some input on a dose, post your preshot number twice daily and ask others what they might do.
I think you'd said you feed wet, low carb, right? You might add that to your signature so we don't ask all the time.