Unavoidable 
The mix between different types of content is unavoidable, because you can assign to a LOTE3 track any type of content by ticking the appropriate box. For example, when I wrote the unHagiography post I ended it with a suggestion to make it into a session, which would naturally be under the ununMonastery track; so I ticked the box. Later, Bembo wrote this post in which he makes more or less the same proposal, and he also ticked the box. Neither his nor mine are structured proposals (I later edited my post to untick the box). Maybe we need a page on “how to present a session proposal”.
But even if we have that, the field called lote3 reference is not designed to indicate session proposals, but rather relevance to a particular track. So you can most easily use it as a kind of feed (“What’s new in track 3”), with everything relating to that track going into it. Maybe we should reword the help text in “Is this post a session proposal? If it is, tick the box of the track it fits in”