Valve lash caps??

I have run them on all race solid rollercam motors, dating back to 84. All those setups were .750 lift or more although the need for lash caps would be there for any aggressive solid cam profile or Ti valves/small stems. I always assumed their function was strictly to protect the valve tips, providing a bigger contact area as well. I have never had one come off, despite some serious rocker and pushrod failures.