The manuals for my 70 Series GCs don't say anything about restrictions on full loads. Would be curious as to what your manual says. Can't imagine there's anything other than changing the recoil spring to a full 16 lb involvolved.
This is a decades old discussion, and one that seems to have no clear roots.
The "stories" included battering and loss of accuracy, for one.
I guess if the recoil spring wasn't changed there might be some. On the other hand, I have read, and agree, that "match headstamp" ammo is some pretty stiff stuff.
Another was the adjustable sights would be damaged in some fashion.
Or the trigger pulls deteriorated from pounding. There are a few weird, extra bits in the trigger system, but I have no idea if they are that delicate.
My personal take:
If you want to shoot stronger loads, match the recoil spring to the load and have fun shooting.:rock:
I happen to like guns that rattle a bit, but that's me, I guess.
The slides haven't been internally lightened since the early '70s. I have a gun with a S80 Gold Cup slide, and if anything, it should be heavier than a Government Model slide, due to the extra material contained in the rib. The Elliason sight can be a problem. I don't know how much mileage my slide had on it when I got it, but within a few hundred rounds, the roll pin broke, as did both the windage and elevation mechanisms. Clamping a sliver of shok-buff, or other resilient material between the sight and the slide supposedly helps the sight's life span, as it prevents the sight from bouncing off the stops with every shot.
For what it's worth, we build a Commander that had the same internal lightening cuts as the GC into a .45 comp gun, and that slide went five years of fairly heavy use. Never had an issue with it, and it was running great up until the time of it's theft.
I've replaced quite a few broken pins in GC rear sights, and we replaced quite a few sights with Wichitas. Other than that, I never saw any "battering".