Most of the authors are not active at the weekend as well as it may take up to 5 working days to get a respond.
Apart from that, Envato license is clean about how you use it ( 1 license = 1 domain / end-product ) and it’s not transferable
Even if you own both of the domains, you cannot change the end-product once the item is activated/enabled. My suggestion would be don’t wait for the author respond and purchase a new copy for your new project.