When in prone or on a bench if not using a rear rest/monopod, or using a simple squeeze bag, your left hand is supporting the stock (as many match rules dictate). Position your dope book, ammo box and other tools necessary to executing a successful engagement within 12" of your trigger hand. After releasing a shot, do not move off the gun, do not move the gun in your shoulder, grab your next round and load into the action, grab the grip and realign your sights. Close the action with your bad lever and prepare to shoot.
If recording data, spotting from a separate scope, needing to acquire a new target, etc, lift or turn your head slightly only. Do not remove the gun from your shoulder. Only if making gross adjustments where you should be resetting your entire position and NPA again anyways. When I'm shooting long range with iron sights my spotting scope is set up so all I have to do is open my left eye and the scope is right there. I may make notes to my dope about wind condition, light conditions (mostly for irons), mark my score book for call vs print, but I never actually break position or have to so I am ready to send the next round down range if conditions are holding favorable.
The whole point of building a good position is that the trigger hand has almost no influence in affecting the rifles position as the front rest, rear support, and head/sight alignment stays intact. Shooting sub MOA at all yardage encountered takes a bit of prep for the shot, it's just a new routine to develop. Sling, bipod, mechanical rest makes not much of a difference, everything should be set up to allow you to focus only on the next shot. Breaking position to release the bolt with your left hand really destroys all consistency.
I don't really subscribe to many of the YouTube videos on prone position beyond the basic fit parameters, i.e. being perfectly inline with the rifle, having a 90° bend in right knee, etc, but being in a totally relaxed state with bone support only is the key. Think dead weight and using no muscle. That is what will give you repeatable shots on target, on different days and yardages.
Anyways, longwinded way of explaining the reason for a bad lever, but for an AR they can be an important piece of kit.
Fear is just excitement in need of an attitude adjustment
Thanks again Alexander. This is not only interesting, but very helpful.