I monitor my mite counts early in the year by vaping with OA as soon as the weather allows. It was about 2 weeks ago for me this year. If I get a high might count, I will continue vaping at 5 day intervals, if not I will stop. I figure the sooner I treat after winter, the fewer brood there will likely be, and the longer the interval until the supers go on.
I will not check again until the supers come off. Well - that's what I did last year! I know I should monitor throughout the summer, but I curently only treat with OA, and would not use it why supers are in place. So I figure, no point in monitoring if I am not going to treat.
If I get a swarm I will vape them, or if I have a hive that has swarmed and is thereabouts broodless with no honey prospect, they may get a vape too.
As others say, drop counts can be misleading. I don't like the sample 100 bees in a cup technique and don't want to open hives unnecessarily, especially this time of year.
I know hitting them with one vape to gauge the situation has its + and - points. But when I factor time/cost/disruption to the hive, etc, its what works for me.
I know my whole treatment plan is in some ways questionable, but in other ways good. So I see it as a fair middle ground.
It will probably have been changed before the year ends anyway....