I would think it would be the same as placing the pedals in the amp’s effects loop which puts them between the pre and power amps, just like you would be doing running the F-2B > pedals > power amp. As with a combo amp with an effects loop, some pedals, like modulation, tend to do better in the effects loop while others, like gain and overdrive, often sound better between guitar and amp. Go ahead and experiment, you aren’t going to blow anything up.
Bill, the guitar one.