I should note I also have small hands and run an extended slide release. My thumb doesn't interfere with it upon operating the firearm because my hand is smaller, though that happened all the time on my 1911 and I did needless amounts of tap-rack-bangs when I ran dry, assuming it was a malfunction.
I'd also note that when practicing one-handed reloading and shooting drills to simulate an injured arm, an overhand slingshot probably isn't possible if your hand is ruined severely. Dropping the slide by catching the rear sight on a holster only works consistently if you're running kydex on an OWB. It's much more difficult with a leather or hybrid IWB. It also keeps the muzzle away from your threat for a longer duration. You can always try racking it against your belt as well, but I find popping the extended slide release with my thumb works great during one-handed drills because I can do that with the gun on target, instead of adding the extra step of trying to send the slide home off my holster or belt. The gun is already out of the fight long enough when you're trying to pop in a fresh mag with one good hand. I can also do weak-hand, one-handed reloading drills and pop the slide release with the second knuckle of my now-trigger finger.
The dexterity of hitting the slide release is a lot less than doing the knee method or trying to catch the rear sight on a belt or holster, IMO.
One big benefit of the RMR optic I run is it makes it incredibly easy to send the slide home. I just bat the RMR with my support hand instead of gripping the slide to slingshot it. I remember during a weeklong training course, my adrenaline was pumping so hard that I was practically palm-striking the Trijicon during reloads. I actually managed to bruise my palm pretty good. It also catches much easier than a tiny rear sight for one-handed reloads.