Currently we can add only new attachments to posts but can we add attachments if they are already in Media Library (of course we should have access to our own attachments in the Media Lib but everyone could view those attachments if they are added to posts not to PMs)?
I am not sure why I cannot add multiple attachments at a time to comments now. Only One attachment at a time can I add when I edit a comment. Please check it.
Please check why only some attachments: pictures when added to post and are being clicked are not displayed in the popup (so we can zoom in/out etc). I believe it is way convenient when even large images are displayed in a popup.