Sorry, but I think that would be bad.
FI, what if you have a level where one quant has a "game" scale of one inch,
then another level/game where the game-scale is one quant = one foot.
It would look awful.
Its got to be up to the level designer to decide on the "viscosity_scale" that
"matches" both the game-scale of the level, and the "type" of fluid being represented.

[EDIT] Getting this thing frame-rate independant is being a real bastard!