I would assume that with the Eclipse Designer client coming along that this will be included by default, but you're right it would be a nice thing to have.
This seems like a good idea for someone to do as part of a general "NotesLint" tool, but it seems like it should be done outside of IBM to encourage innovation from multiple sources.
I created a little app a while back that did just this (and other stuff) called LSCalls. You can find it here { Link } My version is a command line app that dumps out a text file, but Chad Schelfhout created a little Notes database that pulled it back into documents all nicely categorized and what not. You should still be able to find that here: { Link }
A more general idea would be for Designer to present a list of "warnings" when compiled code contains things that compile OK but look dubious. Some other IDEs have had this functionality for years. I think I'll submit this as a new idea (if there isn't one like it already).