What about when IP and user-agent aren't sufficient to get unique visitor count?

[Daniel15]

• Environments like schools and businesses often have an identical setup across all their systems (meaning each one has the same user-agent) and have just a few public facing IPs.
• Some ISPs have deployed CGNAT, which means hundreds of thousands of customers may only have a few dozen public IPs. (They should really be using IPv6 instead of CGNAT, but that's a discussion for another day).
• All people connected to a particular VPN server will generally have the same outbound IP.

In all of these cases, I think the number of unique visitors in Plausible will be inaccurate, potentially counting all visitors from the school or business as a single visitor. Now that major browsers are freezing the user-agent, it won't be as useful to differentiate users from the same IP.

IPv6 solves most of these issues (except for hits from a VPN of course). Many ISPs have made huge progress in deploying IPv6, for example some of the large mobile phone providers in the USA and Australia have IPv6-only networks (using 464XLAT to access legacy IPv4-only servers), but there's still many bad network operators that haven't deployed IPv6.

Does Plausible have any plans to better handle these cases?

I don't care about tracking individual users across multiple days (which is what commonly sparks the privacy issues); I'd just like a more accurate unique visitor count per day.