I can get up to 3 coats out of an ounce. My trick is to use 60CC syringes. It allows me to really control how much I'm using as well as waste very little (assuming I do 3 coats at a time when using ZFX). The great thing is if you don't accelerate with ZFX if you are doing one coat you can just put the product right back in the bottle when you are done if you have any left over.
I'm not quite sure how you got two coats out of a quarter ounce of Z5. That's amazingly thin or you missed a bunch of panels
