Being new to this keto thing, I still test with a Keto-Mojo device very regularly (at least daily, sometimes more as I continue to learn about my intraday variability). At some point I’ll know enough about my metabolism to lighten up but for now it’s very educational (and encouraging).
To answer your question: I appreciate that glucose in the morning and BHB-ketone readings hours later just before lunch might be of greater interest. But the only drawback to testing glucose and ketones at different times is that you probably can’t make much sense of the “GKI” (Glucose’Ketone Index) that results from the two being measured at the same time - see Keto-Mojo website and other web sites for details.
Is that a big deal? Well, in my case, I found surprisingly high ketone levels in recent days - high enough that I began to worry - that is, until I considered that my glucose level was well controlled in the 70-80 range. Super high ketone levels can indicate ketoacidosis (very dangerous) but only if your glucose is quite elevated too … mine wasn’t so everything remains perfectly great. But I would NOT have had this reassurance if I hadn’t been measuring ketones and glucose at the same time.
If your ketones aren’t especially high (mine were quickly climbing @ 4.9, 6.1, 6.9 …) then I can’t see any reason not to take tests separately as you wish.
But just a thought… while the Mojo test strips run around $1 each for ketones, the glucose test strips are pretty darn cheap. So… after you test for glucose in the morning, why while not test for glucose AGAIN while testing your ketones? Then you can begin to track your GKI reading once a day also. 