Hard-link tasks to allow earlier project completion
Allow to "hard-link" tasks in a way that the following task will always start after a pre-defined number of buffer working days (excl. weekends, holidays) after the end of its (linked) successor task. This would allow to also estimate earlier project completion in case tasks are completed earlier than expected along the line.
This functionality does exist currently for the extension of tasks (following tasks will be pushed backwards) but not in the opposite direction (following planned tasks will not start/end earlier even if the predecessor ends earlier).
Ideally this functionality would keep the resource occupancy in mind and offer options if shifting the tasks to an earlier time would lead to task overlaps for the same resource. Options could e.g. be e.g. starting the lower priority (or non critical-path) task after the overlap, change the resource etc. - for the meantime: at least warn. See also here: task-timing-based-on-resource-occupany