We have asked because I agree, if we had to start paying to upgrade the suspension then it would be madness. Whether we will get a reply who knows! We asked another company when we looked at the VW Sprinter 6.8 metre van in another range and got a load of waffle so that made us wait and we ended up not buying and no regrets.One thing I would ask for before tempting yourself further is ask them to weight a new one with all the pre-installed kit on, full water, some fuel (if they can tell you accurately how much that would be useful) but NO people on board and let you have the individual axle weights, that way you can see if, even upgrading, will give you enough allowance on the rear axle as I suspect it won't.
The other thing putting us off is the lounge, we actually love the comfort and layout, and are used to putting a table up each time as we have a U shaped lounge. The big but is that in the evenings you'd be surrounded by the cab windows with no sign of any nice Remis blinds on the horizon and no one like Taylormade make good external screens yet. We think it might well feel chilly and certainly would feel rather spartan which after all that money would be a pity, not cosy like our IH630RL.
I'm glad I posted, as usual there have been some useful tips.