Hello - Looking for some help with Customizable Campaign Influence in Lightning.  Does anyone have experience setting this up and be able to explain some things in detail? Specific questions I have are:

1. When you switch on Campaign Influence you receive a message stating, "we're recalculating campaign influence. Wait until we're done before updating any settings on this page." Does switching on campaign influence actually try to build CI records on the new CI object or do those records only get created going forward using one of the attirbution models?

2.  On the Salesforce PrimarySource (locked) model - how is the primary campaign on an opportunity determined if there is more than one contact associated to an opportunity and each contact is associated with more than one campaign?  Is it the last date that one of the contacts was associated with a campaign (as long as it is before the oppty close date)? Is it the Primary Contact on the opportunity? Can I see on the opportunity which campaign is identified as the primary? I am having trouble getting this model to show influenced opportunities on the campaign. I see the campaign influence on the opportunity, but the influence and revenue share are 0.00%.

Thanks ahead of time to anyone who can shed some light on this topic.  I've been digging into the details and playing in a sandbox, but am not seeing what I would have expected.