another idea -- having the fx chain list represented in the same media item properties box
and then the fx chain box could be different for the media properties, showing the position in the top pane
unlike other sequencers, it could also be used for instruments and midi tracks no? picture a midi sequence, just a little part, and you dont feel like assigning it its own track. Just make the midi part, and in the properties send it to a vsti!
simple as that!