plugin is causing white flash with loading ab testing code

Hello I am using the premium plugin and have a problem with VWO code, ive added the smart code (there name) to the plugin list and its causing a white flash.
I spoke to them and they recommended to add within a condition if user accepts then this else so on.
Ive actually found a condition added on this forum and tried and it works, however its in the footer and the vwo code needs to be in the head, is there a solution that you know off ?