Atomicman--remember that exercises and drills (i.e. the penny in the boot cuff), valid and useful for developing skills and discipline as they may be, are not skiing, and they are not racing. They are exercises. I'll bet that the coaches did NOT put pennies in their athletes' boots when they were racing, and I'll bet they wouldn't scold Laure Pequegnot for losing her pennies in that winning slalom run (or Bode Miller either)! Real skiing is about skills matched to tactics, about versatility, and athleticism--not about "this is the only right way to make a turn" dogma.
Phil and Steve Mahre relentlessly practiced their weight transfers and one-ski balance, and advocated "outside ski to outside ski" like fundamentalist preachers preaching against sin. But their famous "White Pass Turn" defied their own rules--and won races. Their coaches thought they were errors!
I contend that many top racers excel DESPITE their coaches, not because of them--and that includes Olle Larsson. I've heard and overheard and observed some incredibly bad technical advice from even high-end race coaches!
It is obviously true that a ski cannot engage its tip if there is no pressure on it, as you suggest. But the way skis are designed these days, in shape, flex pattern, and torsional stiffness, pressure focused on the "sweet spot," somewhat aft of center, will be distributed along the entire length of the ski. No further forward movement of the "center of pressure" is required to get those tips to engage! Furthermore, when skis are tipped to high edge angles, it is ROTATION of the feet and legs that pressures the tip or tail--not fore-aft pressure on the boot cuffs. The higher the edge angle, the more obvious this becomes. (Clearly, a ski lying its side must be TWISTED to produce downward pressure on the tip. Any "forward" pressure on the boot cuff would simply push the tip away. It is notable that movements that control pressure distribution when the skis are flat become rotary movements when the skis are tipped to high angles, and movements that twist the skis when they're flat become fore-aft pressure control movements at high edge angles!)
Not that it matters, but since you asked, my second-favorite pair of slalom skis in my current quiver is a genuine World Cup stock Elan SLX. These are not "race stock"--they are true World Cup stock. So yes, I am quite familiar with how such skis perform--I'm not just guessing. They definitely do NOT require forward leverage to get their tips to engage! FastMan's "tripod" (heel and 1st and 5th metatarsals) will bend the entire ski.
Here's a little animation that shows the principle clearly:
Again, this is NOT to say that fore-aft leverage is always bad. Racers, and all expert skiers, must develop skill and comfort across the full range of possibilities, if for no other reason than to allow them to break the rules effectively. When you have skills, you don't need rules!