Yes, this is supported and can be especially useful if you want to clearly distinct your primary domain from the sites that are deployed. This setup would look like this:
Storefront at yourservice.com - Your storefront & landing page to sell your product(s)
dashboard.yourservice.com - This is your Dollie-powered customer/site management area.
<sitename>.yourservice-sites.com - Your deployed sites using a different domain then your primary domain.