If I use Yottaa DNS, can I change back to my previous DNS provider?

Yes. You can revert your list of deleted name servers back to their prior settings at any time through your Registrar. We do recommend that you make a copy of the current settings along with a copy of your DNS current records to facilitate this change. Yottaa will not retain a copy of your pre-change DNS records.

Also, moving the DNS service away from Yottaa DNS will not deactivate the Yottaa Optimizer service.