Yes, I see. But we don't need eVar for previous page name. We just want to define Total Page Visibility to eVar (not to events as how in documentation mention s.pvel='event7,event8,event9'), something like this s.pvel=' ,eVar10, '
The plugins requires 4 variables: one eVar for capturing the pageName value and 3 events (two of them are optional) that will become metrics. If you implement it according to that documentation, all the values will be set automatically.
So in your case the minimal setup will contain one eVar and one event that you need to configure in the report suite manager and also set in the implementation code (see the doc).