Nothing would be bad really. Since your wrist is made to go only in four motions, I would keep the heavy levering to those 4 and don't rotate. I wouldn't go heavy at all for figure eights and things like that since you can easily mess up your wrists since they are not made to withstand a lot of force in those directions.
When I said don't go to heavy, I meant don't go out and buy a 12 lb sledge. I levered a 8 once or twice to my face so I went and got a 10 lber, almost got a 12. I was so close to buying a 12 (figured I'd just choke up and work my way down), but I decided not to. I think even the 10 was too much, since it took me a while to be able to lever it. I should have gotten the 8 and worked with that, then gotten a 10. If I had gotten the 12 I wouldn't have been able to move it. Also, I am only talking about levering to the face. My 10 is a bit awkward to choke up on for front levering and doing things to the side.