Sand em quick with 400 wet.
Then high build primer to fill the craters.......apply high build fairly thick, so ya have lots to sand down.....sand with 400 till smooth, then scotchbrite to make sure ya don't see sanding marks.
Worked awesome on mine, and took no time at all......glass smooth.
If this was on a panel that flexed alot, this wouldn't be the best way, but since they really don't flex at all, it should be fine.......I did a test panel first and flexed it by hand, and it didn't crack the paint.
I love that smooth painted look...really finishes the bike off.