The actual difference between 000ppm and 008ppm is so
small it makes no difference at all.
I use water straight out of my tap(
yes terrible i know) at
present its at 33ppm the lowest its ever been and i never have
a problem.
Rinse more and the windows that dont take to it,which there will
always will be some(more in bad weather conditions)simply blade
dry afterwards.
Wfp isnt a cure all,simply adapt your technique when necessary
and you wont have a problem