I'm sorry, but you don't know what you're talking about.
OK I admit that I don't know everything about browsers and I hadn't looked closely at WebKit's definition of a page cache. Reading it properly it says that the page cache is used to 'pause' a page when the user leaves it so that it can be very quickly re-displayed when the user presses the back button. That does sound like it could also be used for swapping between browser windows on the iPad.
However a quick experiment should show whether the 26Kb limit on the page cache is causing the reloading problem. Take two pages, one and two. Measure their sizes (in this case 65Kbs and 33Kbs, just for the HTML), load them on an iPad in separate windows and see if you can swap between them. On my iPad this works fine with no reloading so I'd conclude that the small page-cache isn't the complete answer to the page reloading problem.
Look, I'm not saying that the page refreshing isn't annoying however throwing around 'answers' that haven't been proven doesn't help anyone.