Brunswick's polish is usually considered an abrasive. So whatever is grit level is under the polish won't remain there for long.
Powerhouse polish is usually considered a non abrasive. Whatevr grit level is under the polish will retain more of its effect.So if you start with 1000 grit + this polish and find it too early, resanding with 2000 and adding the same amount of polish will usually get you more length. This effect is seen from the dullest sanding (500 grit), well into the finest sanding (4000 grit)
With Brunswick's polish you'll see less and less difference once you're at about 1500 grit.Remember Brunswick used to apply this polish over 400 grit US/Cami sanding about 10 years ago.
"None are so blind as those who will not see."