Inconsistency between "Select more" and "select to end of flow"

In my case, I’m trying to copy one entire instrument to another instrument. I don’t see how the system track would help with that.

I can do “select to end of flow”, which is what I have always done. I just thought I’d try the “select more”. By ignoring the triplets, I don’t see how I could ever use that, unless my music doesn’t have any tuplets, of course.