The issue with using teh sidebar area (without the external resource plugin) is that users will attempt to insert an image from a url, but this does not add it to the media manager and won’t work with ACF.
Yes that makes sense, it is really only once you get into a highly customized situation like mine that the need for this arises.
Perhaps the best solution is to add a JS filter on the args so you can customize them for the image field?
Yes I think something like this would be perfect.
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