Yes, it is possible. You are free to install our extensions to TEST (development) sites. Only live & running websites are regulated.
Q1: I purchased the template/extension with "Single domain" option, but I need to install it to my development server for testing and customization which has a different domain. What should I do?
A1: You don't need to do anything, just go head and do. Domain Validation is not an automatic system, we are peridically (usually once a month) check the domains that use our template/extension, and compare them in the "allowed domains" in our backend. If we see suspicous activity, first we contact the license owner and let him/her know about this situation. If no response in 5 business days; we take an action and "copyright criminal" banner shows off on the website. If the website is hosted in a domain, something like:
test.domain.com,
www.domain.com/user1/something or http://localhost/ it is obvious that this is a development server (we are also designer and totally understand this situation, every live website has at least one development server/domain). YOU ARE FREE TO INSTALL THE TEMPLATE/EXTENSION AS MANY DOMAIN AS YOU WISH FOR TESTING PURPOSES. Only running and live websites are affected from the domain regulation.