When the little lever is flipped down in the draft mode.......
There should be very little or no slack in the rocker.... but in the draft mode, yes, when pushed in, it should lift and be more sensitive to rocker arm pressure as the lever is move to higher, less sensitive when lever is moved to lower position. But again, its a lot of pressure from the plow..as it has to push the big spring in... if the spring end is adjusted too loose, you can push it in by hand and that is not correct. pull the pin out of the rocker and tighten up the spring end and take out the excess slack, reinstall the pin in to the rocker again.

and with no pressure on the rocker, it should lift when the bib lever is nearly to the top..

Now with the little lever pointed up and in the "position" mode,,, the lift should rise and lower incrementally with the big lever position being raised or lowered..