Congratulations to RONSERESURPLUS!
You are the first person I have, ever, encountered on the internet who knows better than to load a semiautomatic pistol to full magazine capacity +1 in the chamber - Especially in 45 acp caliber, too!
You are, also, exactly correct; and, I have sufficient field experience with a Glock G-21 to verify everything that you have said. If I wanted to guarantee myself a, 'top round jam' within, say, the next 100 rounds all I have to do is continue to load my G-21 magazines to full magazine capacity +1. It WILL happen!
This problem is, also, exacerbated by the use of +10% magazine springs which are commonly used, nowadays, in many Glock 45 acp pistols. (Like mine!) I've had this internet argument on several different occasions and been told that I'm, 'nutz' over at Glock Talk where many of the active law enforcement crowd have acquired the personal habit of loading to full magazine capacity +1 as a matter of daily routine, and insist there isn't a problem.
My point (and now your point, too) is that: Sometimes you can get away with it; and, sometimes you can't. Because of other variables like different: spring tension, bullet ogive, your grip, and feed rail design, a 45 acp Glock pistol is the very last handgun I would want to carry at full magazine capacity +1.
(But, hey, as I've often said: Feel free to do whatever you like. I mean, after all, I ain't the one standing behind your gun!)
Yes, again, I'm another old gunman who carries his Glock in C-3 and regularly practices using a (modified) Israeli draw; i.e.: Support hand over the top of the slide, palm down, all the way back and release. On smaller frame semiautomatics I use the slingshot method of pulling the slide back between my thumb and index finger.
As far as I'm concerned: My family is safer; and, I am more at ease with loaded weapons inside my home - Where if something can go wrong, it WILL go wrong. Sure, the question could be asked: Am I in any greater danger for routinely carrying this way? No, I don't think so. Just disadvantaged, perhaps, by the need to use two hands on the draw.
In fact, if anything, I'm a little more alert than most other of the other gunmen I know. This is because I recognize the slight disadvantage C-3 carry entails, and constantly seek to stay one step ahead of whatever's going on around me.
PS: Because it, probably, needs to be said: Would I endorse C-3 carry for law enforcement use? Not in America, I wouldn't! C-1 is the right way for American law enforcement to go.