Every time I post this, I wind up ruffling some feathers among the 'crank it down and leave it' crowd, but ignorance deserves to have ruffled feathers.
The biggest thing most folks can do to help them take out most of that up/down movement is to fine tune their tiller to their own shooting style. Just setting tiller to zero on each end with the bow at brace height (static tiller) rarely gets the job done. Your grip might put more pressure high up in the handle, the next guy's grip might put pressure lower on the handle Or vice versa. How/where pressure is applied in the handle can change the relative strength of each limb during the draw/aim/shot sequence (dynmanic tiller).
In an attempt to forestall the inevitable argument....While the actual strength of the limbs don't change, the
balance of strength does. Imagine the bow is a seesaw with 35 pounds of weight on each end, and your hand is the pivot. As long as your pivot is exactly centered between the weights, the seesaw stays balanced. Change the location of the pivot and you have to adjust the weight on each end of the seesaw to keep it balanced. When the pressure is off center in your bow's grip, then the weights at the end of the bow/seesaw must be adjusted to balance.
When one limb is stronger than the other, the bow will try to pull up or down while you're trying to hold on the target. To adjust, hold your sight pin on a target, then slowly begin to draw. Watch the pin.
If it wants to pull UP, off the target, then the top limb is stronger in relation to the bottom limb. Back off the top limb bolt , add too the bottom limb bolt, or both.
If it wants to pull DOWN, then the bottom limb is stronger in relation to the top limb. Take off on the bottom limb bolt, add too the top limb bolt, or both.
Keep adjusting until that pin stays stable all the way through the draw cycle. What a bow does during the draw is exactly what it will do during the shot, just backwards and slower. If the bow wants to pull up during the draw, it's going to KICK down during the shot. Any movement from the bow during the shot will be transferred to the arrow, which will affect speed, accuracy and tune-ability.
Fine tune the bow's tiller to fit your grip style, and you'll have a lot easier time controlling that up/down movement at full draw. And your bow will be easier to tune; it will shoot smoother with less recoil; it will be quieter, more accurate and maybe even faster.