Then why is the effect both predictable and
consistent?

it isn't. Most recreational sailboats made in the last 40 years will exceed
"hull speed" without any heavy lifting, and Hobie cats will go 3x "hull speed"
or more.

Some would argue that those hulls are planing, though plainly that is not the
case.

btw, mathematically the extra effort needed "to climb the bow wave" is zero at
"hull speed" and still doesn't amount to all that much at 2x "hull speed".

the THEORY is not theory at all, but oft repeated hearsay.

When the results of an experiment conducted a million times are identical in
all regards, at what point can one draw a conclusion without being guilty of
voo doo science?

You could make a case that, under unique conditions, a vessel in displacement
mode
will attain speeds (in knots) greater than (sq rt of waterline expressed in
feet) X 1.3. You can make an accurate case that the multiplier for specific
hulls may vary between 1.2 and 1.4.

What cannot be argued is that beyond the calculated hull speed a vessel meets
the resistance of the bow wave, and must start climbing that wave (leave
displacement mode) in order to increase speed.

Exceptions prove the rule. If I observed that it is possible to have a rain
squall pass 20 yards away and stay perfectly dry, that would neither
establish
that such a lucky break is a common occurence or that water isn't wet. :-)