The bolts on the front corners adjust the apron hight. I believe i do have to adjust the linkage going up the tounge every pass otherwise it would always be digging and never carryingI'd run it a while with a ratchet turnbuckle so you can adjust the angle till you get it where you want it, and then leave it there. I don't think it needs to be adjusted every cycle.
Why does the hitch have a couple inches of play up and down? and what do those bolts on the frame near the front corners of the tumblebug do?