You may want to tell Tasty and Krizwit that they should stop breaking thermodynamic laws then as they don't seem to have a problem doing it or anyone else that I know that brew 10's in 25 or greater capcity kettles.
I not sure about what you are posting, however, I believe it to be false, by your statement then you could not boil a gallon in a 2.6 gallon pot either, which I think everyone would agree is not accurate as about everyone has done this on their stove. You may want to go back and re-evaluate what you have read, you may possibly not be interpreting the data accruately.
The physics of water won't allow you to bring 10 gallons of wort to a boil in a pot that can hold 26 gallons.
It has something to do with the Dioxygenic-thermalexnophobic nature of water in the presence of so much empty space. As the water seeks to occupy the unused part of the pot the natural thermodynamic event takes place of lowering volume and temperature as the water deconstructs through a vapor phase change point. This is exacerbated by the fact that vapor pressure is affected by the addition of heat. The result is that no matter how many BTUs you pump into the bottom of the pot the water will simply seek to change phase to fill the rest of the pow trying to achieve homogenous phase of water throughout.
So the long to short is you cant get there from here.
As for brew pots:
If it's SST or Aluminum you are golden.
I've run into the problem of rust in most Chinese Stainless Steel. Most pots are now made to work on induction cook tops because, as we all friggin know, EVERYBODY on the planet will have induction cook tops by maybe the day after next. So they are using a 400 series Stainless. But there's a catch (hey it's friggin China there is always a catch). The friggin Chinese SST sucks. They don't use enough chrome or nickel to actually get the stainless to self passivate. So the metal rusts pretty damn quickly after exposure to many food acids or heat.
Isn't that nice? Came to me as a really butt-fuggin-ugly surprise.
So if you can, pester the retailer or manufacturer to determine whether the pots are 400 or 304 SST. You want 304 if you can get it.
Brown Halco makes an aluminum pot that is fully 1/4" thick. I almost got their pot.
1/4" means you can drill and tap your threads right the hell into the pot for all your ports and valves and dip tubes etc.