Whether Avast in one of its products, can introduce the possibility of preview in the session record for outgoing and incoming connections, i.e. www addresses and the ip number with which the user connects, eg the Avast SecureLine VPN application.
Avast already has a register of such sessions set by the user, it may not be a problem to provide such service to its clients.
I think that it would be a great solution and appreciated by many users. You can limit the preview in sessions to 24 hours for its preview, with the ability to save the session results by the user to a file on your device. Session connection control is normally difficult without root in the system. The option available in the application mentioned above will allow to satisfy curiosity and gain the trust of users. Personally, I am able to pay extra for this service;).
If the VPN stores all kinds of information on your system,
it then becomes very easy for some unwanted entity to access that information. (IMHO)
Store nothing and nothing can be gathered.
you are right, with the difference that you can encrypt such data, you can read VPN data saved after the end of the session or give the user only information about connections without cookies and a private or public key.
If you say it is not secure, I think you must trust Avast if you store such data on your server.
I also thought about another solution, about the idea.
VPN can be used as a connection record, sometimes just looking for security. The user can then see which connections and sessions he installs his system and applications if you do not have a firewall.
Thank you for your help. Maybe it speaks for a good solution to my thoughts;)