I've only sampled this thread, so I'm sure I'm repeating someone, but it certainly needs to be repeated, if so.
"Large effects" of mutation are not a problem for Darwinian evolution, at all - if by "large effect" you mean large phenotypic effect. What *IS* a problem would be the necessity of multiple simultaneous mutations. That kind of "large" mutation is not part of Neodarwinian theory.
"Large phenotypic effects" and "many simultaneous mutations" are different concepts.
"Saltationism" that proposes "large effects" of the first kind are part of neodarwinian evolutionary theory. Simple as that. No conflict, whatsoever.
"Saltationism" that proposes "large" mutations that require many *simultaneous* mutations are not part of neodarwinian theory.
Personally, I don't see the need for either of these for the evolution of mimicry, as Dawkin's explanation that you quote seems like obvious common sense to me, but even if the first kind of "saltationism" is necessary, it presents exactly ZERO challenge to contemporary evolutionary theory.
I can't imagine this hasn't been brought up in 13 pages, but there it is again.
Edited by Zhimbo, : typo fix