If you select some tracks in Audio mode and then change to MIDI mode, when you jump back to Audio mode the track selection has been reset. The same happens when you select MIDI tracks and change to Audio mode and back. Note that variation selection stay where they were.
Fast adjustments on selected tracks while switching back and forth between modes, and a consistent user experience.
It was the main part of this wish: Remember knob parameters when switching between Audio/MIDI tracks
Also related to: Ability to switch between MIDI sequencer and audio sequencer’s perform mode straight away, without switching views