thanks for fixing this in v22.214.171.124.
re: "Display options for inserting galleries / single images into a post?" in media options —
i believe ideally these options should be separated, as one might want to display one (say, gallery options) but not the other (single image options), or vice versa.
moreover :), right now i'm working on a project where i'd like to display both buttons (insert gallery, and insert single image), but _not_ the options, as they'd only distract and confuse the user (hence my previous report of the 'display caption' not on by default). what i'm doing right now is setting the defaults in media options, and then hiding these filegallery controls with display:none in my custom admin css (which works quite well due to your nicely organized code and IDs for pretty much everything, additional thankyou for that!).
i can also think of a situation where i'd want to display both buttons, and the options for just one of them :).
in other words, i believe this level of interface customization would be fantastic, it's something that this plugin lacks right now, but it's also what it deserves, taking into account how incredibly good it is in most areas.
it just takes custom backend development for wordpress to a whole new level, i can't believe i hadn't found it earlier. i'll most certainly be back with more ideas (if you don't mind) and bug reports (if any).