When I'm in a 320 mode program and the screen blanks with the Messages module, the screen is left in 320 mode... T2 should set the MasterSCB and SCBs of all the scan lines to either 640 or 320 mode based on the wantGrafPort320 bit.  In addition, it'd be nice if the palette was set to zero for each scan line when the wantGrafPort bit is set.  I think I've mentioned this before (in the source code comments?), but it can't hurt to remind you, eh?  :-)

When I change a value in the setup dialog and then either close the window or choose another setup item from the pop-up menu, I almost invariably forget to hit the update button.  A nifty preference for T2 to have would be "Prompt for updating" when something like that happens - I could turn it on and a dialog would say "You forgot to update the setup.  What do you want to do with the changes you made?  (Ignore) or (Update)."  That can be turned off for people who don't forget so easily.  :-)  This, of course, assumes that you put in that Hit message allowing the Update button to be enabled when a hit on a control that requires setup information to be updated.  :-)