setting both IC and IDL quality to 100 (max) in poser render settings screen forces IDL samples to 2024 and IDL IC to 95, as shown above.  the IDL precalc method causes a different result with each duplicate render, hence blotches will be difficult to reproduce exactly when IDL IC <=95, but may always be located near the problem area of geometry or displacement, hence it wouldn't work to try successive duplicate renders in hopes of cancelling out the blotches.

does the SSS precalc algorithm also use this monte carlo method?  if so, that would add to the uncertainty of the blotch location and appearance.  I don't know which variables could be set by the user for SSS that would be analogous to setting IDL IC = 100 (giMaxError=0, skips IDL precalc step) and setting IDL samples to 2048 or 4096, but apparently the latter are not helping with the SSS displacement blotch bug.

p.s. ipad users may benefit from the bluetooth keyboard, however a note of caution: take out the batteries from the keyboard before putting it in one's briefcase and going for a ride somewhere.