Yeah that's one option... we each have to just experiment with feeding to see what works best for our cats
You can Test/Feed/Shoot at AMPS, then feed anytime until +6 and then Test/Feed/Shoot at PMPS and feed again anytime until +6 and see if it make any difference
It sometimes helps to put a * in the cells when you feed so when you go back and look, you can start to see if there's a pattern developing that will help tell you how Jake responds to feeding (or jot it down in the "Remarks" area of your spreadsheet)....that's what I do with China...put how much she ate, when, and what carb % (if different from her "normal" foods)
Another option some people try is to break the AM meal into 2-3 meals and T/F/S at AMPS, then feed again at +1, +2, +3 and then no more food (other than pokey treats) until PMPS (That gets all the carbs into them at the beginning of the cycle when the Lantus is going to be working it's best)
The test I like to get is a +2 because it can give you some early warning if they're going to drop lower in the cycle. If the +2 is lower than the Pre-shot, that's a good clue that they might be dropping lower later in that cycle, so you'd want to make sure to get some tests in (even if it means the alarm clock), but getting a +3 and +6 is great too...but you want to get them at different times when you can.
Think of your spreadsheet as a puzzle. If the only pieces you see are the edges or right in the middle, it makes it hard to see the "whole picture". If you shrink your spreadsheet down as small as possible and don't concentrate so much on the individual cells, you'll start to see place where there's lots of white....that shows you where you need to get more tests so there aren't a lot of those big empty white areas