I think I would need to put a bag of flour on my keyboard if I was to let you play it...that way you wouldn't need to worry about it moving whilst you pound and smear away enthusiastically.

Why not
two bags for aesthetic purposes?
Seriously, 5-6 lbs ain't gonna make any difference...don't be makin' excuses.
Thankfully, I'm not limited by any keyboard's size or weight...I just adjust, like many pros do...you're a pro...adjust.
There are no home arranger keyboards used on stage by "stars" as far as I know, PSR or otherwise and including the G70, although the same keyboard
actions may be used in pro gear, such as the Tyros' FSX being used in the Motif...and I believe the G70's action is in an older Roland A-series controller as well(A-70?), but that's about as close as these instruments ever get to stardom.
If "pounding" so hard as to shift a 25-30 lb
electronic keyboard on a stand can be considered a style, then I am glad it is not part of mine...I like saving wear and tear on joints and tendons and using the volume control...but some have to "suffer" for their art.

Personally I think pounding away on any
modern well actioned
electronic keyboard is more about
theatrics than anything inherently musically useful....technology has moved on, son, and there is no need for it anymore...unless we be wanting the dubiously musical thunk from the key hitting the keybed rail as part of our sound?

The dynamics of my little S900 go from no sound at all when I press a key really slowly, to very loud when I strike harder/faster and every nuance in between is covered admirably...what more would I need than that?
Then again, action is a very personal and subjective issue, so what works for some, does not for others.
Lizt broke piano strings because they weren't as well made back then...or maintained either....metallurgy has advanced a lot since his time...if he had been playing a
Yamaha piano, he would not have needed a spare instrument and/or strings.
Lizt
had to play hard considering the actions on the early pianos/pianofortes, and pounding, or playing hard, was necessary in many cases, and, no doubt, encouraged so that his many fans could hear him...we have amplifiers/speakers nowadays to serve the latter.
Enjoy whatever you choose to play, and look after yourself, my friend...hopefully you won't be long catching up to the rest of us who have figured out that heavy gear is unnecessary in this day and age of vastly improved and responsive keyboard actions and lightweight materials, and, hopefully, you won't wind up with pain meds and/or back surgery as has happened to many who stubbornly refused to change.
Ian