Workarounds for Macintosh /M=messagestr in e.g. NewPath

Before OSX 10.11, it was possible to display a little message telling the user what sort of file to pick from a dialog box using /M in for example NewPath command. This is no longer a possibility and I'm wondering what workarounds other people are using? I can build a panel with more information on what the user should do, but I'm wondering if there are more simple solutions.

From the help file:

As of OS X 10.11, Apple no longer shows the title bar in the Open File, Choose Folder, and Create Folder dialogs. Consequently, the prompt specified by the /M flag, which was displayed in the title bar, is no longer visible. Apple still shows the title bar in the Save File dialog.
I suspect the only options are to have the message displayed briefly before the dialog box (e.g. "In the next selection window, choose on .TXT files") and/or to have a help-button with the instructions. Using the flags on the Open command to restrict file choices is important as well. Finally, since even the most in-your-face message can sometimes be ignored, we still have to create a file loader that gracefully handles even the worst-case situations that we thought we had directed the user to avoid. The try-on error construct, where the try portion does a test for proper format before reading the full file, helps in this case.

J. J. Weimer
Chemistry / Chemical & Materials Engineering, UAH
Thanks for those thoughts and ideas. I could definitely handle "user picks the wrong thing" scenario better in my current project.
For what it's worth, it looks like we'll have a workaround for this problem in Igor Pro 8, so the message string you provide with /M will actually be displayed.