integration with automation services such as Zapier, automatorwp, automatorplugin, etc. I need to send a WhatsApp or SMS notification to specific users when an admin gives them access to a certain file
so I need to be able to form some sort of webhook for zapier or other WordPress automation plugins to be triggered.
Your Plugin already invokes sending e-mail notifications to users, so it may not be a start from scratch thing. Hopfully.
My point is your plugin idea can be a powerhouse once allowed to trigger actions in one of those automation plugins.
I have included a resource from one of those plugins websites "the one I use", for you to get some hints if it is a do-able feature. please consider it. https://developer.automatorplugin.com/
I still didn't buy the plugin, but if you are planning to work on this feature soon, i will be happy to buy and work with you in testing this feature if you want, because i really need it.