Just tried MC17 for this feature, since I'm having trouble with Harry Potter and the Deathly Hallows Part I defaulting to the wrong video title (commentary).
I think this feature is a nice start in MC17, but I hope we can see some improvements/fixes soon. This is with 17.0.38.
Top of my list
1) (from mojave) Rename titles
2) (from rpalmer68) Don't immediately switch titles - give the name, then ok button switches
3) FEATURE: Allow the default title to be set, so the title doesn't need to be changed manually (i.e., for Harry Potter 7, Part I)
4) ISSUE (Bug?): Display settings (changing to 23 fps) are not kept when changing titles. I guess some titles will have video formats, so you can't assume the FPS tag applies to all. Need some tags for each title?
5) BUG: If I stop playback of a non-primary track, starting playback again appears to go to the stopped timestamp in the primary track. Should resume the last played title, I think.
6) FEATURE: Love the idea of getting track names and info from a database (alternate ending, included shorts) so it is downloaded with the standard movie metadata. Even better, the ability to combine multipart movies (the LOTR extended blu-rays). This type stuff is obviously harder than 1-5, but I hope you are considering this type of stuff.