Do you mean dual enrollment as in part homeschooling, part elementary school, or part elementary, part middle school?
I have experience with the latter, though in that case it was middle/high school.
The main issues are transportation, which for us was OK because the schools in question were very close, and scheduling - which might not be a big issue with elementary because of not having blocks/periods, unless a special class like music or gym is at the same time.
There's some minor issues and conflicts but you really just have to take those as they come. But it seems like they're fairly cooperative, which is very helpful.
Although field trips are just....ugh. The scheduling is horrendous sometimes.
