Quote:...snip...You don't need to flatten to export! (as png, jpg, webp, whatnot)
Well, you just might need to flatten especially if the 'whatnot' format is PDF and your image contains a text layer. Typically for sending off to a print-shop.
Gimp still does not correctly embed a font in a PDF and when opened in a computer without that font, it is replaced by whatever is default.
Still the same old cure for that - flatten the image. (although you can also use new-from-visible)