Hello Benjamin
Unfortunately, we have not progressed further with https://theeventscalendar.com/knowledgebase/using-one-license-live-dev-sites/. If your site does not meet that requirement, you can certainly still use the plugin on the site, but cannot activate the license. All features for our plugins will continue to work, but you will not receive notifications regarding updates (to be done manually). If during that time you require support, please remember to manually share your System Info with us.
If you’d like to acquire a pro license to ensure that your staging site will receive updates and can share the system info, you could reach out to our support for a prorated upgrade price.
Please send an email to support [at] theeventscalendar [.] com.
Thanks
Courtney :)i