I like the packArgs trick. Also easy to add an arg to the sub for selecting one of the options.

the canvas within this BANG app resizes fine for each of the chosen packArgs.

But pls try this:
* split the PackForget() and pack() over 2 buttons (show, hide) one containing the packForget, the other the pack
* start the app, and resize the main window
* then hit 'hide'

The canvas and mainwindow are not resized.
I seem to be missing the point about the resizing through a call to geometry. Can't find a hint in the docs either.