It is added as a normal surfactant just before coating. It is used at the normal level. If it is not, then coating defects result.
IDK why it causes the effect. It is a development accelerator though, and that is all that I know. I was directed to the patent by a friend after I observed the effect. It can be attributed to either Poly alcohols and / or poly ethers. I have no more information at this time, but hope to get some at the end of the month at our next GEH lunch.
See what happens when I take advice? More work for me!