Fluffy dream on!!! Have you ever fired a 25 ft lb gasram? Of course it is technically possible to achieve that level by pumping up the ram but it would be horrible to shoot like that and I suspect the piston would need recrowning very regularly indeed.
The ultimate gasram technology is incorporated in the Eliminator not the HW90. If you want that sort of power then don't muck about-get an Eliminator.
Calling an HW90 a gasrammed HW80 is an interesting one. I don't see it myself. I think the HW90 is a quirky rifle with an indifferent trigger that I have no desire to own let alone uprate. I wouldn't dream of taking up a slot on my ticket with one when Eliminators are so cheap and so much better.