> The most challenging thing about it IMHO is how to correcltly handle not only one instance in the visualization but many, say millions, without forcing the us

> The most challenging thing about it IMHO is how to correcltly handle not only one instance in the visualization but many, say millions, without forcing the user to pre-aggregate and loose all the interesring details. I wasn't sure what you meant by pre-aggregate here. By 'instances' do you mean the states of the User data in time?