Interestingly, I switched the container to visit (vs. default visitor), trended my fall out point, then 'show data', then manually averaged the revealed data - that was within a single percent.  I can live with that. 

Jennifer, this is a great summary.  Thanks.  

D'oh.  I should have known that, thank you.  

Jennifer, Thanks. Lots of useful thought starters.  I dragged the utm_medium directly over so it would be a hit-based segment.  The mid-session email opening is a possibility by in my industry, likely an edge-case so I won't worry about that.  The use of 'instances' is a good suggestion.  Thanks aga...

Thank you, that's exactly what I was hoping for.  

Thank you for the answer, but no, i was really looking for a visit/session id.  I'm trying to debug a high bounce rate.  I know what and how to get the ECID.

Thanks, this is very helpful.  We populate the the pageName value but don't use it much.  We have an eVar1for pageName and an eVar2 for URL. We rely on the eVar1 almost exclusively. That eVar1 should be set on every page (and it is attached to most events).  Page DpageName = "paged";eVar1 is not set...

this happens to me on visits. Does that mean there are visits where no page name evar has been set?  

Thanks for your response, I really appreciate it.  I do have a data lake team, but the lack of a page name of every hit is an issue for them as well.   A technical fix is to just change the implementation, or add some code to prevent reloads and see how it goes. I think that is the route I'll have t...

Thanks very much, sincerely.  But this explains my problem without solving it.In your opinion, could this be solved by using a visit container, where reload exits an then within one hit "page event is equal or less than 10" (to capture multiple page events).  I then use this to segment page events. ...