"BUT you must configure it. You must delete the values"
How else should the system know what are input data and what are to be calculated data? and of course, you cannot calculate in any direction, but you can assume it works from left to right. Example
a) You edit a product, you change the net price, the product had a discount, you set for the discount 0.0 => you will get the final price and tax calculated based on the discount.
b) You edit the same product, the discount is done by a calculation rule based on percentage, you empty the discount field => a new discount is calculated and a new final price and tax.
But always, when you write something in a field, it is not overriden. It is imho a lot better than in vm1.1, but seems that even moderators dont know about.