"DSK" wrote heh heh reduced windage, greater
efficiency... a snowball
effect... at what point can you have infinitely large sails with no
mast at all?

Oh, so you want to follow that progression down to the end do you?
(I'm assuming this is a joke because, if you understand this as well
as you say you do, the answer is already obvious.)

All else being equal, the mast can get smaller as the rig gets larger.
At the same time though, the amount of wind that will heel the boat to
any specific angle is getting less since the righting moment is being
decreased by the weight of the added spars and rigging. The sails
could never be infinitely large because the added weight of cloth,
booms, and gaff will eventually bring the center of gravity high
enough that stability is zero. At that point, there will be no load
on the rig from wind and the mast could be infinitely small if there
were some other way to transfer the loads from the sails to the hull.

--

Roger Long