Same smart folder across libraries

I am often confronted with having mailboxes and single mails (eml, emlx) in my libraries due to how my workflow with filing things is. Now what I do every time is to create a smart folder that lists all eml or emlx-files (= single mails) so that I can merge them with the mailboxes that eventually already exist in this very library.

Is there a way to have EagleFiler this kind of smart folder automatically included when I open a new library?

(Bonus question: Is there a better way to find single emails not in mailboxes in a EF-library?)

EagleFiler can display .emlx files, but it does not support merging them.

You could copy the smart folder .plist file into the new library’s folder. Do you often create new libraries?

You could do a Filename search for “.eml”. I’m not sure whether that’s easier.

Thank you!