I just got the Unimold starter kit - I have read the guide showing the process but am a bit unsure of the process between the coupling coat and the final reinforcement layup. Before laying up the final reinforcement Do you 1. Allow the coupling coat to completely cure. 2. Allow the coupling coat to tack, or 3. Apply the final layers immediately over the wet coupling layers.

It's BETTER to leave it overnight. Last thing you want is the styrene to attack your gelcoat and cause alligatoring. It may be cured enough after a few hours, but it's a risk.