well, first you need to buy a poke light type weapon (ex short spear) cuz it can make you go forward and backwards. After this, for switch poosting you need to attack with melee and immediately switch to bow to cancel the backwards momentum (this need some practice).
Or if you prefer longer poosting distance you can try to 180 poost, which you need to attack with melee and immediately turn around to transform the backward momentum to forward one. I hope I helped you :)