R93s particular model replaces the slide lock pin, they lock in place and don't protrude into the frame far enough to be tripped by the magazine follower, they also don't have any up and down movement like a normal slide lock so applying thumb pressure to them doesn't lock the slide back. Nice piece of kit, have one on my open gun.
The problem with the 1911/2011 design is if you have the slide locked open and try and shove a big stick into them too hard then the mag can actually force its way far enough into the grip that it hits the ejector and breaks stuff, the mag catch is the only thing stopping it from doing this and can be over whelmed with the force you can apply to a 29 round mag when reloading on the clock. If you use certain shaped projectiles and/or load a long oal the projectile can also trip the slide lock prematurely, most open shooters will disable the slide lock back feature. I know of some standard shooters who do as well.
+1 on this.
I haven't come across many other standard shooters with a functioning slide lock. You shouldn't be running the gun empty anyway. :p