Option to never export jpeg/tiff "comment", and see but not export png comment
When exporting as png there is a check-box option for not exporting comments, that nicely stays checked if the user chooses to save default settings for exporting pngs. But the actual comment (if there is one) is not displayed.
When exporting as jpeg or tiff, the comment is displayed and the user has to erase the comment to not export the comment.
Why it matters:
darktable and it seems a number of other editing softwares insert a comment telling the world that the image was processed using said software. Maybe there is a way in various softwares to say "don't embed any comments". But the user would have to track down the right settings for all the software they use. Other software such as digikam allows the user to type in comments that might be something they'd prefer to not share with the world, eg "Uncle Sam wearing his stupid face" is something a user might not want to share with the world.
The comment metadata field in GIMP somehow seems to be treated differently than other metadata fields.
It would be nice to have an option in Preferences to never, ever, ever under any circumstances export any metadata at all including all comments.
In the export dialogs, ideally there would be for all file export types two things:
A checked box (that stays checked until the user unchecks it) to not export the comment (as png has).
The ability to see the comment (as tiff and jpeg have).