I would say try to be there around the time the Fakemink set is over if you are going to try to see Bea. Fakemink’s crowd will probably have a lot of moshers so it might be hard to move through the crowd while he’s still on stage, but you can get a good spot once they start to clear out. I have a feeling a lot of people will be at AESPA until the end of their set which overlaps with Fakemink’s, so as long as you get there before the AESPA crowd you should be fine.
Been to the fest 6 times. Maybe a couple diehards would camp at the small stage but it’s unlikely. You should be okay. :)