What are the rules for re-entering Thailand with a DTV visa after 180 days?

You don’t need to stay out just comeback it multi entry for 5 years

There is no 180 day "rule."

The DTV visa gives you 180 day permission to stay each and every time you enter Thailand. Whether you enter 1 time or 50 times in a year, you will get a brand new 180 day stamp every time. There is no limitation. If you leave Thailand you do not have to stay out for a week, you don't even have to stay out for 1 day. You can return the same day and get a new 180 day stamp. Or you don't have to leave at all and can apply for a 180-day extension from your local immigration office one time per entry, but leaving and returning is much easier.