Give the sealant 24 hours for it to fully "cure" or you may run the risk of it being moved around as you apply Natty's.
If you get to see some of the Poorboys World Detail day pics, you'll see my SC430 which also has EX-P topped with Natty's.
We also did a small test.. Souveran vs Natty's. Not that big dramatic difference. I'm sure on black it may be a bit different.
Enjoy your new Poorboys products! :bigups
Regards,
Deanski