You asked.... Beyonce is a POS. She treats everyone terribly... roadies, band members, backup dancers, sound board, EVERYONE. Nobody likes her and they all avoid her.
Madonna... very similar. Disrespectful to road crew and the locals that work security in the arenas. Most nights won't go onstage until after 11 pm. Very mouthy and curses a lot.
Mariah Carey similar to Beyonce but not as bad to the crew.
He hasn't worked with Taylor, so no story there. He hasn't toured with Rhianna either.
He has toured with several others not on the list... but he says hands down Beyonce is the worst.