A couple quick idea to help manage worker timeline
First, give outline task folders optional start/stop dates which are then applied to the folders children tasks. Offer warnings if the sum duration of the children, taking worker availablility into account, exceed the range defined at the folder level.
Second, the reverse of the first, an option to make a folder's timeline dynamic and reflect the sum of the children taking work hours into account per worker resource.
These would require defined work hours per worker. It would be interesting if a user's availability could be based on a percentage of those work hours on a per-project and all-project basis.
Thanks for reading and good job on a nice tool