New Jenkins UI allows collapsing Build Queue & Build Exec Status panes.
That is very good as list of slaves and their execution threads can be very long.

Unfortunately the width of left menu & Build Queue & Build Exec Status panes does not reduce when Build Queue & Build Exec Status panes are collapsed.

I'd like to propose reducement downto width of longest menu item (likely Job Config History) when Build Queue & Build Exec Status panes are collapsed.

This enhancement enables to better use right part for showing more columns of a list view (which is not scrollable in new UI design).