I don't shoot any release trigger guns Brent - but it would be pretty easy, to keep the gun pointed downrange and the trigger pulled back and still release the lever and open the gun - and remove the shell if you want - and then release the trigger so it does not fire.
Most of the release triggers I've seen are on single barrel - break open Trap guns like a Browning BT-99 or the BT-100.
Its only my opinion, but I think most flinches are the result of eye or vision issues - blurry vision, lack of focus on target, etc vs bad triggers - but in either case, I know some Trap shooters that swear by release triggers and wouldn't order a gun any other way ..../maybe a shooter with bad arthritis or something where pulling a trigger smoothly is a problem ...
I've never seen a release trigger on a semi-auto or a pump gun .... although they may make them. But it would be pretty easy to hold the trigger / then open the bolt and remove a shell - while still holding the release trigger ... Keep the gun pointed downrange and trigger pulled - operate the pump with your off hand / or open a semi-auto bolt with the off hand ....but that would make me really nervous if I were the shooter standing next to that shooter on a "Trap Line" ...
Does that help ?