Lets be clear and realize that like many things, there is a difference between what one can do, and what one should do. And lets also realize that reloading data are GUIDELINES and not hard and fast rules that always apply equally to everything.
The history of the .45 Colt round is rich, and begins in 1873, with the Colt SAA. And black powder and balloon head cases.
And even though improvements were made to the ammo, for nearly 100 years the standard gun was the same Colt. A bit improved when they changed from the "black powder frame" guns, but still "THE" .45 Colt.
After Ruger introduced their new model Blackhawk in .45 Colt, on their large frame, people began experimenting with loads heavier than the Colt gun could handle, literally rivaling .44 magnum power levels.
And speaking of which, the Colt SAA in .45 Colt is the reason we have a .44 Magnum, today. Elmer Keith blew up (at least) 3 Colt SAA .45s seeking the power he was after. Existing guns simply weren't up to what he wanted to do, and so he switched from the .45 cal guns to .44s because the extra metal in the cylinder allowed him to get where he wanted to go without the gun failing. I often wonder that IF Elmer had been able to use a Ruger Blackhawk, we'd have a .45 Magnum, and not a .44 Magnum. But that gun didn't exist then, so we have the .44 Magnum, and now "Ruger only" (or Tier 3) level .45 colt loads as well as the original level loadings.
I dearly love the .45 Colt round, and I've had my days of running it at or even exceeding .44 Mag in my Ruger, and about 30 years ago settled on a 250gr bullet and 10gr Unique as my standard load. Its powerful and not unpleasant to shoot, and while a max load in a Colt SAA or a clone, its not a dangerous overload should some of my ammo get into one of them by accident. (I don't currently own any Colt SAAs, but that's just my preference) Had a NEW VAQUERO, which is Colt size and in that gun I didn't run 10gr only 8 and it was just fine, too.
I've got some 4 5/8" and 5.5" Vaqueros, too and out of them, 10gr is noticeably less pleasant than it is out of my 7.5" Blackhawk. 8gr is very fine, though the guns will take significantly more, its less fun, and I shoot them for fun.
If you've got a load that is good in YOUR gun, and fun to shoot as well as being plenty powerful, go for it, and don't let anyone tell you that you need more. The speedometer may go to 120 but unless you're racing, 65-70 get you there plenty fast, with a lot less stress.
Everybody's data is a little different, because the guns and components they used are a little different. Your combination of gun and components may fall in the middle of the bell curve like most others, but it is always possible you could be at either end, so reloading data is guidelines, NOT laws.
For example, if you get sticky extraction (or any other sign of excess pressure) at 9gr, DO NOT go to 10 just because some book or online data says that is max.
The point to make accurate ammo that does what YOU want. If you've got that, you don't need to go anywhere else, do you?