There'll be lots of 'cheese' fights. They like classes to be able to excel at specific fights. I can't see from the videos whether the legs are close enough together, however. It seems unlikely you'll be able to spread to all the other three.
I'd expect it to work like madness. You can't spread your dots onto the things which spawn (blistering parasites/congealing bloods/hemorrhage bloods etc) but you can spread from them onto the main body/arms.
Likewise, you could dps one leg and cleave to the body but not other legs.