My mentor is a commercial beekeeper. He uses chemical treatments for mites every year. No need to check for mite counts. Everybody gets the treatment.
I have read behind and listened to many beekeepers with varying numbers of hives and experience. Most seem to encourage the use of a mite count. Get a mite count by sugar roll, ether roll, or sticky board. Treat if you are over threshold X. Don't treat if you are under the threshold. On a smaller backyard scale, this seems to make sense. On a larger scale, not so much.
Now I have run into something new to me. Beeks who claim to be treatment free, who still do mite counts. I heard one beek make the statement that he will change nothing in his management strategy, regardless of the mite count, even as he loads bees into a jar to shake. I guess I am missing the logic here. If I do not plan on changing anything in my management of the hive, why should I do a mite check? It's just a number in my head, if I won't do anything about it. And, I am probably killing or injuring a handful of bees in the process. And I'm wasting my time to get a useless number.
I'm not trying to say you shouldn't do mite counts if you don't plan on doing anything with those numbers. I just don't understand why you would, and I'd like for someone to explain the logic to me. Personally, I have followed the plan of my mentor in treating automatically. I have 30 hives now. I think that I will continue to treat these hives with the same management style. I also hope to start another yard with treatment-free hives. I don't plan on doing mite counts in that yard, sense I will not be treating them, no matter what. Let the strong survive, and weed-out the weak stock. Should I rethink this issue of mite counts in that yard?