I have a number of sites and they each go through local, dev and production stages, so there's a lot of licence key entry when I'm developing. Some plugins have a method of directly entering your key into the wp-config.php or similar (https://deliciousbrains.com/wp-migrate-db-pro/doc/activating-license/#wp-config) and I find this quite useful for plugins I use often that require licence keys.
I've had a quick look and I don't think this is something motion page does, but it would be cool if it could in future, pleeeeeease 😍