I don't like the broom shaft example. The skis do not care how the forces between the boot and the binding are created. It cannot tell if a force comes from heel and shaft pressure or even under foot pressure.
In a "normal" balanced position the pressure center should be slightly less than 10cm (4 inches) in front of the ankle joint center, and that point should coincide with the ski's sweet spot.
If you are skiing with 4G forces you cannot have only heel/shin contact. BoF, Heel AND shin contact is required. It is not an either or thing.
I only skimmed this tread but I think a major point is missing, and that is how the for-aft relation must shift throughout the turn.
Assuming you are fore enough when you put the skis on edge and set the edges the hooking up of the ski will shift the force under the ski forward due to the increased bending of the shovel part.
If you are just standing around in static fore-aft balance at this time you will inevitably be pushed into the back seat, because the GRF is forward of the CoM. This is especially true if you are already standing on your heels and shin because then the only compensation you can do is to push on your heels.
You have to meet this shift of pressure proactively, i.e. the CoM has to be moving forward over the skis in the turn initiation (or equally the skis have to be moving aft in relation to CoM).
After this, If the turn is carved the fore-aft will be pretty fixed during the turn phase and the CoM will move aft again as the forces are released.
If the turn is brushed the initial CoM position is more fore, and it should move progressively aft throughout the turn.
Sometimes you have to be extra much forward in order to bend the shovel of the ski more. For example with the last years 35 m GS skis you often had to do whatever you could to bend them.
In a "normal" balanced position the pressure center should be slightly less than 10cm (4 inches) in front of the ankle joint center, and that point should coincide with the ski's sweet spot.
If you are skiing with 4G forces you cannot have only heel/shin contact. BoF, Heel AND shin contact is required. It is not an either or thing.
I only skimmed this tread but I think a major point is missing, and that is how the for-aft relation must shift throughout the turn.
Assuming you are fore enough when you put the skis on edge and set the edges the hooking up of the ski will shift the force under the ski forward due to the increased bending of the shovel part.
If you are just standing around in static fore-aft balance at this time you will inevitably be pushed into the back seat, because the GRF is forward of the CoM. This is especially true if you are already standing on your heels and shin because then the only compensation you can do is to push on your heels.
You have to meet this shift of pressure proactively, i.e. the CoM has to be moving forward over the skis in the turn initiation (or equally the skis have to be moving aft in relation to CoM).
After this, If the turn is carved the fore-aft will be pretty fixed during the turn phase and the CoM will move aft again as the forces are released.
If the turn is brushed the initial CoM position is more fore, and it should move progressively aft throughout the turn.
Sometimes you have to be extra much forward in order to bend the shovel of the ski more. For example with the last years 35 m GS skis you often had to do whatever you could to bend them.