I’m thinking about ways to make the UI better.
I think the Apple recommended way might be what they do in Text Edit… add a special toggle command Format > Make Plain Text / Make Rich Text. And once you do that then when you save you’ll get a different set of saving options.
Unfortunately that seems almost as hard to discover as what I’m currently doing. Instead I think I might make the save dilogue look like this when you save AND your document has text formatting attributes:
You won’t get an explicit alert telling you that your file format choice will loose formatting attributes, but it’s still pretty clear I think. Seem OK?