Yep, that's ^^ essentially the same theory as the VWR mount. I believe it is a subframe off job??, so you'd have to re-do the alignment too.
Sloppy mounts and bushes cause wheel hop.
The force of the torque when accellerating rotates the engine backwards. The wheels pull forward in the well, pulling on their bushes altering the angle of the wishbones. This makes the wheel move from a toe-in to toe-out position. As the tyre then breaks grip, as the increasing toe-out eventually reduces its contact patch, everything rotated/stretched then bangs back into position.
It isn't an 'up and down' motion in terms of the wheel/suspension, more like when you play on those bungee ropes when you try and run as far as you can before it snaps you back.
A diff won't cure it, neither will tyres - all you're doing there is moving the threshold at which breaking traction occurs. The WALK kit in terms of its added caster, the poly bush within the WALK is what's helping there... any changes to static geo settings are pointless, as it's the dynamic that alters. Inserts don't make any measureable difference on their own either and again, the only way stiffer suspension helps is by keeping the nose from rising, making it keep traction for longer before it breaks. Knackered/poorly matched dampers however can have an effect.
If you want as OEM a solution as possible, then you need to focus on removing the weak links in the pendulum mount and wishbones. Powerflex do replacement bushes for all areas of these to tighten them up, with the exception of the VWR/HPA style mount. The S3 wishbone bushes are a option of course too, but you'd still need the rest.
