.....is it an absolute requirement to take the child nowhere at all?

I could do the three day thing except she has swim lessons fours days a week. They are Mon, Wed, Thurs, and Fri - so no consecutive three days off. Nondisposable swim diapers required.

The lessons are only ten minutes long and located <10 minutes away, so it's a pretty short time. Is it enough to derail potty training, or should I just wait until she finishes her lessons in August? She'll be three in September and shows all signs of readiness.