A feature that I believe some outliners have and I think
would be a good implementation in Progect, is allowing a
child task to show up in the flat mode (or on to-do list,
if linked) only after the "grand child(ren)" directly below
it are all checked off. Perhaps this could be a
preference setting, but I would find it very useful.
Parent: Change Lightbulb
Child: Put In New bulb
G-Child: Take out old bulb
When you check off G-child, then the child will
automatically show, and remind you that the next step
you need to do is to put in the new bulb. But it
shouldn't show up before G-Child is done, because you
can't complete that step until the light bulb has already
been taken out.