> Eli,  do you think this would be acceptable ?

Actually, after I replied, it made me think..

Instead of a mysterious lonely "+" argument, would it make more sense to a
descriptive argument like "--files-with-linenum-colnum"?

Eli and the emacs-dev list, feel free to suggest if this is a good idea or
if a different argument name is more appropriate.

Of course, emacsclient -help should show this new argument.