I think that would help, but I think it would be even more helpful to have a dV counter showing how much dV (including decimals when it gets really small) is left in your burn. The burn indicator bar is fine for rough burns but when you need to be super exact it's not very helpful. Also, imagine if, on your navball, there was an "Opposite of maneuver node" marker you could auto-point at for when you did your burn just SLIGHTLY too long and you need to reverse!!!