Not sure what you mean - What does "when the valve springs are completely open" mean? The springs are neither open or closed. It's the valves that are open or closed. The springs are simply more compressed when the valve is open than when it is closed.
When the valve is completely open (open at peak lift), it does so because the rocker are has pressed down on the valve stem tip and opened it. Only the rocker tip or roller should be touching the valve stem - no other part of the rocker arm should be touching anything but the valve step tip. The rocker should not touch the spring retainer, and it definitely shouldn't be touching any part of the spring. With a hydraulic lifter system - that same part of the rocker arm, the tip, should be in contact with the valve stem tip all the time - whether the valve is open, closed, or anywhere in between. And at no time should the rocker arm touch anything but the tip of the valve stem.