Issue: Allow setting id/class on custom [div] position="sidebar"

How do you expect to use this? For security reasons, users cannot update classes or styles on the outermost sidebar element (the one marked with class bbWrapper). If a user wants to apply styles to the content, they can place another DIV inside the sidebar DIV.

If you as the admin wants to be able to apply styles to a particular element, I've gone ahead and added an attribute customid to DIV/SPAN/WIDGET in the next release. The attribute is only relevant in positioned contexts.

When you use it, like so:
The block will get a class that looks like "vw-block-customid-my_custom_id"
As an admin, you can use it to write CSS rules for those blocks. For security, do not give them any rules that modify overflow or CSS position. Outside of a sidebar context, you should use the standard/whitelisted class names that are available to you.