You have to be very carefull when mixing small quantities.
If you mix 85 + 85 gr from two diferent cups you
may (
:pinch
have a problem.
When you stir B component into A, you have to asure to drain EVERY GRAM.
I mean: If 5 grams from B stay on the cup's wall, it represent about a 6% of the B component. You will be mixing 85 gr A + 80 gr B.
This % of lost material is bigger as the mix is smaller.
What you can do to avoid that, is to mix on the same cup.
Stir the A 85 grams first. Then, on the same cup, add another 85 gr B. Then mix everything carefully.
(always mix each component separately before mixing)