Hi James
Sienne and I are big believers in the +2 test as it will give you an idea if it's likely to be a busy cycle or not. If the +2 is similar to or lower than the preshot, you should expect an active cycle. So, if at night, you can get a +2 and before bed, that would be great. If you are up by +10 or +11, those are also great tests to get but if he's high when you go to sleep, there's no reason to get up just to test.
I agree with Wendy....it is much better to pick one meter and stick with it.