This License Plugin looks very unprofessional from the consumer's view.
When purchases are completed, the user needs to wait for a separate email other than the order confirmation to arrive in their inbox. Quite often it is caught in SPAM folders, which you will need to direct your customers to check their spam folders for your commercial keys - YUCK
This plugin does not work with Variable products either, if you are interested in selling different types of product keys, you need to create separate product pages for each - which has really gummed up implementation.
Please be aware before purchasing.