One of the biggest things I get fustrated over with is selecting a bunch of trees to cut down one by one or selecting berry bushes one by one to be picked.
So, my suggestions is a feature that enables you to drag your mouse over a group of trees or berries and you will be able to select them all. From there, you could tell your workers to cut down the trees or pick the berry bushes.
In case you want something slightly more acceptable, you can try rp_click_and_gone.
Not drag-and-drop but it’s making life much comfortable already. I’m not sure if there’s actually a way to get all entities inside a box already - I would think there is - so this might be implemented as some sort of mod by somebody someday too.