So after landing some Vulcan pilots would always select the 1-to-7 transfers forward to make sure that the C of G was well forward!
An aft C of G will probably make stalling characteristics more dramatic due to reduced manouevre stability from the lower tail volume. I had some fun demonstrating this effect to a group of pilots a while back in a T67A. This is only allowed to aerobat at quite low weight - and the fuel tank is in front of the cockpit. So with a chubby crew, the maximum fuel load allowed was very low - we'd weigh the crew, check the fuel level, calculate how many more litres it could take and then add fuel very carefully. This had the effect of moving the C of G aft, fairly obviously, so that stalling in the turn was noticeably more playful and it would flick very readily if provoked. But with a lean racing snake in the other seat, the fuel load could be greater, the C of G further forward and it was much more docile!