a high tee helps, but there is a flatish-straightish spot in the bottom section of the clubhead ellipse so alignment and ball position relative to this part of your flatspot is crucial.
if your numbers are down a lot, you may have to feel like you move ball position a lot to re-orient your whole show to strike the ball at a different place(further along, up past low point along a bit more then into the up) in that ellipse, or you can alternatively or simultaneously alter the tilted plane (hsp and vsp) of that whole ellipse to re-orient your strike.
i can get significant upward numbers off quite a low tee, and still catch it near center. the above concept along with a well loaded shaft that matches your plan helps too i think, maybe a softer tip that is lagging/drooping so the head is rising behind the grip more/later.....
