I'm using a Manfrotto 475B with the legs minimally extended and decently angled out as necessary:
When I mount everything up as tight as I can get it, the most flex in the system is clearly from the 405 geared head - the small gears they use, even after locking them, just have too much flex.
I hear what you are saying about damping, that must be there too, but first order is to get a lot of the flex out of the system. I can add damping later if needed (I am an engineer that theoretically can figure this out).
So, I have the 475B tripod->3/8" bolt->Manfrotto 438 Leveling Base->3/8"bolt->405 Geared Head/QR Plate->3/8" bolt->Arca-Compatable Clamp->Short Plate->1/4"bolt->600/5.6 Tripod Foot
Occasionally if desperate I will extend the column a bit, but I usually don't need nor want to.
- John