Missing shortcut key to open Bookmarks/SourceTree pane

Earlier versions of SourceTree (prior to the visual refresh that I think was added in 2.x?) had the ⌘+B key binding to open the main SourceTree (previously called 'Bookmarks') window pane when the app was active, but another repository was opened.

This appears to have disappeared sometime between 1.x and 2.x, I'm not sure exactly when as I migrated from a fairly old version up to the latest (2.3.1) recently, and didn't take note of my old version sorry.

When I try and manually bind an action to ⌘+B in Settings > Custom Actions, it says I can't as it is already bound to 'Bold text', but I can't even see where that is used (doesn't appear to be in the commit message box for example).

Is there any way to bring the key combination back? For now I'm just using 'Don't restore windows on startup', but I still have to switch through ~10-12 windows by the end of the day to find the bookmarks window

Thanks, and keep up the great work on the app, it's brilliant!