> If the hiring manager can't see the relevance then I'd rather not waste my time with them.
You have to understand that hiring organizations have layers of people, your resume passes through a few human filters before it gets to the desk of the manager who posted the job, and not everyone in that filter process knows Agile ~= Scrum so you have to factor according to the lowest common denominator.
... and some hiring managers would communicate that to HR, but honestly, to HR people it all sounds like R2D2 talking to the trash compactor. You got to imagine some key deciders reading your resume has no clue what any of it means, they don't want to know what it means, but they know when strange words have the same spelling.
Ultimately I agree with your original post to an extent. It certainly doesn't hurt to include the appropriate keywords but I wouldn't lose sleep over it.
You have to understand that hiring organizations have layers of people, your resume passes through a few human filters before it gets to the desk of the manager who posted the job, and not everyone in that filter process knows Agile ~= Scrum so you have to factor according to the lowest common denominator.