Hey @LStokes
I’d agree with @karstenkoehler’s recommendation, especially since Apple’s privacy changes, correctly measung engagement with marketing emails is a bit of a grey area; particurly if your engagement metric is “email opens” instead of “email clicks”.
One other approach I have seen and implemented for customers is working with lists. Let’s assume you have a series of lead nurturing emails which provide additional information on topic A. You could create an active list for anyone who has clicked a CTA or specific link in one ot the nurture emails for topic A. And then use membership of that list to assign a lead score.
This approach wouldn’t offer a weighting, unless you start working a list per email and then use and rules to assign larger scores. But then Karsten’s suggestion of increasing a “count” property becomes equally as feasible.
Hope that helps.