Rahul from rtMedia team.
Our add-ons work perfectly without license keys.
Our plugin does not send any data unless you add a license key. We need to send license key and related data to our server. Otherwise how we can verify licenses and track activations?
The new law is not in effect yet and as I said before we will take necessary action before May 25.
Our license handling mechanism is handled by a library from https://easydigitaldownloads.com. The same library, I believe, used by more than 1000+ premium theme/plugin provider and likely active on 100k WordPress sites across the internet.
We check license once a day only and use WordPress cache to store results. It appears that on your site some other plugin is flushing cache frequently.
We do not do any kind of data mining so unnecessary check puts a load on our server as well without us benefiting from it either good or evil way.
Rest, we are following the issue closely and expecting an update from WordPress core team for plugin authors. The core team in its recent blog post https://wordpress.org/news/2018/04/gdpr-compliance-tools-in-wordpress/ talked about the plan to put:
New section on privacy will be added to the Plugin Handbook. It will contain some general information on user privacy, what a plugin should do to be compliant, and also tips and examples on how to use the new privacy related functionality in WordPress.
Once new guidelines are there, we will make necessary changes.