Sounds like in the threads I was reading he did get some tiny bubbles from pushing too hard with the rollover. But sanding then a cut and polish got rid of them.

Have you tried a brush, does it not leave noticeable strokes/lines or do the self levelling properties tend to make that somewhat of a non issue?  One other question that wasn't clear from the threads I read, is it advisable to give the playfield a light sand first to help it bond or it doesn't matter?