This issue contains the discussion around adding a second side bar. The secondary side bar would be the next step in improving layout flexibility.

A primary motivator of the second side bar is to address the scenarios expected in #26777.

The current step is understanding the various UX options that could be used to solve the problem. Below are some notes from the current exploration.

• Side bar is a loose term here. We could introduce a second panel instead which already knows how to move to multiple orientations.
• Second may also be limiting. As many have pointed out, should we just allow N number of panels or side bars? Limiting the number does simplify things like keybinds and general layout management and adding too many comes at the cost of complexity that many users will find less useful.
• Currently the panel and side bar solve nearly the same purpose but the panel is drawn differently. Could we adapt the panel to turn into a side bar when it is on the left or right and then make more of them?
• If we go with a second side bar, is it necessary to have an activity bar?

Also adding some mockups from @misolori