In Windows, you can raise a dialog that something has happened. Notify the user when the configuration is in place. Add notification to second checkpoint. Leave 1.5 as is. There's a definition of prompt in the ATAG errata.
Text is the base term.
A text equivalent is a text equivalent that has a recognized equivalence relationship to another piece of content, when rendered in those three fashions, fufills its essential function for those disability groups. Consider ascii art, scripts, etc. In principle, a text element could be built from any format. However, ordinarily, a text equivalent should be build from text. It can have markup, style, etc.