Hi Danny - I'm not really planning on doing this currently... It's sort of a trend in modern UI design to go away from the "multiple document interface" for document editing tools. Meanwhile it is true that it has become more common for web browsing though!

The idea in MoI is to have multiple viewport windows, with a tab system to control those. Putting another tab system in to also control multiple documents in addition to that is kind of getting to have a lot of different window-controlling tabs in there.

Maybe when there is grouping available it will make it more feasible to get what you need all within a single session, with having an easier way to hide/show different blocks of objects more easily? Hopefully that will make a difference anyway.

- Michael