That indicates, of course, that the basic 182 has plenty of structural margin. You have increased the loading, AND moved the spanwise center of lift outboard, and still met structural requirements. Impressive work by Cessna!
Impressive indeed! Now, having said that, they could have done their customers better in some cases. By that I mean Cessna increased the 182's gross on several occasions (strictly by analysis) but didn't allow "already sold" 182s the benefit. An example: For the 1981 182R model, MGTOW went from 2950 to 3100 pounds (1340 to 1409 kg). There were NO structural changes made to allow this, just engineering paperwork. But there was no opportunity for over 4000 owners of STRUCTURALLY IDENTICAL 182P and 182Q (1972 - 1980) models to benefit.
Today there is, only because an aftermarket STC (paperwork only) does for the 182P/Q what Cessna did for the 182R. Don't ask me how I know this.
The Wing-X wing extension mentioned earlier is certainly a great STC for some of the earlier airplanes, but it requires structural mods and costs money.
Can the 182 GW go beyond 3100 lbs? From a true certification standpoint, probably not. I believe it has to do with a requirement regarding asymetrical wing loading. (Float equipped 182s are a special case). On a "Special Flight Permit" they are indeed allowed up to 130% of 3100 with certain operating limitations, but that's a special case.
So, as barit1 correctly points out:
...the basic 182 has plenty of structural margin.
Cheers,
Tom