And technically it would be easily possible with IPv6 to have multiple prefixes at the same time. An ISP could give you one static prefix for incoming connectio

And technically it would be easily possible with IPv6 to have multiple prefixes at the same time. An ISP could give you one static prefix for incoming connections and then an additional dynamic prefix which rotates between customers every 24 hours (leaving old prefixes actives for a week in case you have long-living connections).