If you don't know how to string poly with a drop weight then you probably shouldn't be stringing poly to begin with. You're likely to cause more damage to your racquet.
If poly is too difficult for you to string, then keep stringing with syn gut until you figure it out. It's definitely harder to string poly with a drop weight, it takes finesse, trial/error and a very in-depth understanding of all the idiosyncrasies of your machine. Once syn gut is crazy easy and you've string both stiff strings and soft strings, then perhaps try poly again.
As to tensions, My wrist can't handle poly over 52 lbs, so that's where I keep it. Whether or not it plays perfectly for me, I wouldn't know, as I've never tried high-tension poly.
i string multis between 54 and 56 lbs, and poly @ 50 currently. I get way more control and spin with poly than I do multi. If i'm lazy and don't quite have an as aggressive enough WW finish to my forehand, with poly the ball usually lands in. If I'm on multi, I have to do this crazy WW finish otherwise the ball sails long.
In other words, with multi, it's not applying hardly any spin on the ball -- I have to do all the work. With poly, it's sort of meeting me half way.
FWIW, i've tried poly @ 40 lbs and it was just way too low. No control, no spin, total trampoline.