Tor, you're the man. I wish I'd asked this years ago...
Edit: Oh wait, never mind. Okay, I'm actually clicking that 'Options' button, and nothing is coming up. I tried going on bus with the virtual CG150, and still nothing pops up.
Even so, if I go to the Options dropdown in the main windows and click Global that pops up a window called Program Options. It really would seem like selecting hexadecimal in that window would change the output window as well. Why would it only change the window for putting together messages to transmit but not the output window? I mean the area it's in is Options->Global. There's nothing about that which makes it look like it's only for the message creation.
Edit 2: Okay I figured it out. You have to click to highlight Standard Text Format in that lower part of the window and then click options. Pretty clunky. Still I would think that the Options->Global window pop up would do the same thing.