Have you watched the video of FH driving form that ChrisWoj posted on Youtube? He stresses the usage of legs and the hips and shoulders. Just like a perfect mirror image of standard DGR BH advice.
People tend to forget things i know i have. I hope i remember all my tricks until the spring arrives. What did you pick up from Geoff? Last Sunday we practiced FH throwing with mafa tossing Rocs and Rhynos back and forth. In the end i got much faster wrist action by first training wrist alone throws without any other motion anywhere. Then adding arm pull still standing still. At first i wasn't able to get a good snap from the wrist. Once i did mafa had extra steps to take

It's snowy around here so stand still FH and BH training is needed. If i can add a run up while getting equally good snap with the Avery Jenkins type of pre throw disc waggle then full round swing of the arm my FH leaps forward. Previously i've shied away from training FH and throwing hard because of injuries. Those issues seem to have been alleviated enough for me to start practicing. Unfortunately my rear thigh upper joints don't seem to be strong enough to really push hard in cold weather. I wouldn't want to get new injuries. So run ups are probably best left for next spring. Getting a solid arm action is great.
Once again my snap of the wrist in practice seems to move forward first in the FH not BH throws. My wrist is not super strong i think and i'm way faster and stronger with FH wrist motion. That helps in stiffening the wrist in the elbow chop limiting the wrist motion back from the acceleration. Changing the motion of the wrist motion from a hinge to a spring and i did feel the elongation of the tenser than i'm used to wrist area forearm tendons until the arm was becoming straight and the arm was almost straight when i actively with muscle power flicked the wrist forward. Those throws went nicely farther than the ones with a limper wrist.
Flat shots need running on the center line of the tee and planting each step on the center line. Anhyzer needs running from rear right to front left with the plant step hitting the ground to the left of the line you're running on. Hyzer is the mirror of that.