On first glance it seemed like gantt chart baselines did exactly what I wanted to do - compare an "actual" start/end date to "forecasted" start/end date. When I actually went to go use it, come to find out all baseline does is take a snapshot of the dates/duration when the activity is first added and NO edits/modifications or dynamic updates/linking allowed! This seems like a massive artificial hamstringing of the feature - its such a clean way to visualize comparison between forecasts/actuals (I am constantly comparing projected schedules vs actual) but I rarely care what the forecasted date was "originally", I just want to make sure it lines up with our actual schedule.
The added functionality to directly edit the values in the columns for baseline start/end and/or duration would be a huge boon and allow the function to be way more flexible. It wouldn't even have to modify the existing behavior, it could be changed from the current behavior with a toggle.