I always set the level when the machine is in the ground. Usually on a chisel plow you will set it about an inch higher in the front. The draft action of the chisel will rock it forward just a little when you pull it.
I am willing to bet that it is the shank springs that are causing the bounce. The 712 and 714 have a heavier spring setup on them.
If you can find a set of depth wheels off another chisel then you may try them. The 1710A maybe sucking in too far and then bouncing when it comes back to the set depth.