We all love a beacon with haste II and have efficiency V on our pickaxes, but sometimes it's just too much as you're excavating an area and need to remove a single block.

Is it possible to perhaps introduce a tweak into the client where holding CTRL or SHIFT (perhaps additional user option?) Would temporarily block you from mining more than a single block at a time (or at least introduce a delay, more like creative mode block breaking for example)?

EDIT: For example while crouching on a ladder or swimming underwater also introduces a delay while mining, perhaps this is something the client could mimic manually?