For example, I would like to show an error message that includes the output of a Unix command (potentially quite long.)
I had similar issue and in the end I decided to just create a custom dialog using Spec.
tm := TextModel new.
tm title: 'Failed to do something useful'.
tm enabled: false.
tm text: 'A ' asText, ('lot' asText allItalic), ' of ' asText, ('text' asText allBold makeAllColor: Color red), ' can fit into this box.' asText.
tm openDialogWithSpec
Obviously this is literally the most basic way, I could e.g. compose multiple Spec Models etc.
Peter