Miconazole isn't one of those meds like penicillin where you need to get a precise dose. It's more like throwing some bleach over mildew on a surface. It just matters to get it in contact with the Candida albicans to kill it off just as the bleach solution kills mildew. (Do NOT use bleach to treat sour crop!)
Way back when I first discovered the first sour crop in my flock, I had poor reading comprehension and I treated just once a day with the miconazole. It didn't work. I went back and discovered that I hadn't read the instructions right, and after I started treating twice a day, the hen finally responded.
Therefore, I have concluded that it's more important to keep a steady bombardment of the yeast with the miconazole than to worry about precise amounts.