The longer you wait for the Liquid Wax to harden and cure, the better the results you'll get.
We do recommend 6 hours, but you can even wait a full day. And on the other side, if you don't have the time or patience, you can apply another coat right after.
Everybody details a different way and there are no set rules for how to do things.
If you want to go ahead and apply it right now, you can totally do it. No negative/harmful effects will happen.