Maybe we could just grind off some of the valve stem like the old Ford V8s which had no adjustments.
Actually as the valve wears into the head, the end of the stem is closer to the cam and the spring gets extended slightly.The acorn nut must be screwed onto the stem farther to keep the clearance correct. Thus the length of the spring is the same after adjustment as when new. But all this is just a few thousandths of an inch and is not significant.
The top acorn nut does the adjustment, the lower nut is the lock nut. Make sure the lock nut is tight. I had one come loose once on a 220D and the valve went into the cylinder and the piston came out the oil pan (I didn't do the valve adjustment). The engine still ran on three cylinders but of course had no oil.