Hi gauv, re riding on dirt, I can't remember but I don't think I sent you the link to my crazy guy trip journal of this trip, but about a week or so ago, I rode on a dirt road that at times was very loose, and I was pleasantly surprised by how well my bike handled.. I kind of have a more even weight distribution, still more in back, but more weight in front compared to my light front days. Yes the 2in tires helped, at lower pressures, and yes i have lots of two wheeled experience with "pushing" of the front and using body language and pedaling to keep up right.
Again, if ever you are in Montreal, ill show you my troll setup and you could ride it loaded to see how it feels for you. If that doesn't ever happen, ill be sure to weigh my panniers so I can tell you the front back weight distribution. When I'm back though.