The sections that cannot multi-select folders are those that demand loading a document or data page. These are Documents, Journals and Noteboards.
In order to change the properties of multiple Folder icons and display attributes in one go, use the checkbox options on the bottom of the Properties window. You no longer need to select multiple folders.
I did make some changes to those checkboxes along with fixes, so they work quite well now.
However, if you really must have multiple selection in Documents then I shall add that to the development schedule.
I can see a use for this, such as exporting multiple Documents to multiple files in one go. Not only this but the intuitive nature of multiple selection before assigning attributes is a normal operation. (I think I've just talked my way into the development :D )