First off, apologies Don - I wuz starting to think you were "that dumb" (which still beats "stupid" - "dumb" is usually curable by learning, where "stupid" usually isn't
Second, I WAS "that dumb", never knew Kubota's smaller tractors didn't have position control (all my stuff is old, see my list)
Anyway, if I read your comments right your 3ph has only 2 modes, float or lift? See if this would work to get repeatability -
Set your gear up STATIC, with rake at depth (and attach angle) you want, adjust gauge wheels so they're on the ground - then set some blocks UNDER your lift arms, and try to lower the 3PH FURTHER - this is to make sure there IS no "power down" (you already "fooled me ONCE" :laughing
If the above is TRUE, you may be able to rig a couple chains and/or a turnbuckle of some sort, so that
your 3PH can NOT go any LOWER than those "snubbers" - if that works, then you would just raise the 3PH between passes/turn-arounds, and
lower it ALL THE WAY for the next run - that should get you the repeatability, and it's a few $$$ cheaper than a new tractor
any confusion on what I said please ask... Steve