Trivial connection does work... sometimes. It doesn't seem to work if the pad has a branching track and it doesn't work with vias.
Here is a selection with "Trivial Connection" option:
and here is the one for the same segment with the "Copper connection" option:
Current nightly build for WIndows doesn't have "Unconnected Tracks" option. It's been substituted to track connecting to 2 Nets.
What version of KiCad are you using?
A track is not a segment. A track is a track. A segment is a segment. I would define it as a discrete primitive of a track.