It sounds good...however....
The some of the worst effects of the thymol are in the first 24 hours or so. Chewing pupae out, some agitation, bearding, etc.
If you are pretty confident that your counts are low, then don't treat at all. Otherwise just do the treatment for the full cycle.
Just be sure that your sugar shake was accurate, do you mean a sugar shake on a small sample of bees in a jar or a full hive PS treatment?
Rick
We did a shake of about 200 bees in a jar. The bees were taken from those working on/around the larval pre-capped stage brood. Three hives and the counts were 0,0, and 1 (which is exactly what they were in spring except a different colony had the 1 count along with two zeros) I'm leaning toward not doing anything. No problem requires no solution.