I had this question come up:
"When you collapse tasks within a project, these tasks stay collapsed the next time you open a project.
Especially on large projects, it would be so helpful to not have to collapse the tasks.
I know there are filters and reports, but this is something a little different--and I think it would definitely be cool! I've actually wanted this feature for a long time too.
If this isn't possible, then I might suggest a feature where all tasks are collapsed by default when you open a project. Users could toggle this on or off according to their particular preference."