The following is also an interesting tiny note that shows what happens when one idiosyncratic system is encountered by another user:
[rk via e-mail 07-sep-2017] "BTW: why is the track index significant and why not show its time position?"
This strangeness in Mellite results from the fact that the graphical views and editors are modelled on top of a generic object system, which in turn drew some inspiration from SuperCollider's SmallTalk inherited object inspectors, which are automatically generated GUIs from object properties. In SoundProcesses (the object system behind Mellite), an object is "configurable" through an attribute map, a key-value dictionary with keys being strings given by convention, and values being other objects. In the GUI, you can open the attribute map for any object, this is independent of the type of object. So in the timeline editor, when you select an object, you can view its attributes, which would include, for example, the object's name, perhaps its color if it was given, a sound file associated with a region, etc. The timeline itself is an object type, which associates time spans with objects. Anything beyond that is a "convention" of the GUI editor. Mellite's timeline editor introduces vertical positions and extents for object; this is not defined by the timeline object as such, but simply a convention of storing track-index and track-height in an object's attribute map. The time span, in contrast, is a key stored only in the timeline, not part of the positioned object, and therefore it does not appear in the attribute map. Obviously, a refined editor would provide an observer view for textual representation and editing of the time span.