It would speed workflow for me if I could position the cursor in a note and type S or something to split the note into two separate notes at the cursor position with the right most portion just reverting to “La”.If I decide a word should go up halfway through I now have to shrink the start of the note, insert a new note at the rise portion, type + or - for the lyric.
I would like to split, move right hand portion up, type + or - for it’s lyric.
My wordaround is to shorten the note by dragging and create a new note by double clicking, that’s pretty quick IMO since there’s no need to use the keyboard.
Holding a key and create a little cursor like VOCALOID and FL Studio would be nicer than moving the current playback cursor, the big line is just hard to move around and can only be dragged on the top panel.
What you describe is what I do now also.
I guess I’m spoiled with the way my DAW lets me split events like that.
Oh well. 
I second that!
Notice that “-” must be the default lyrics for the new note because statistically it is more likely that the new note is to build a melisma, or the split is in the middle of a multisyllabic word, causing the word to break if you use “la” instead of “-”.