Can I ask why you're doing this please? The electric seats in mine seem to sit me too high, even on the lowest setting, I feel like I'm looking under the top of the windscreen and it's adding discomfort to my dodgy neck caused from awful posture hunching over a desk for 20 years. I wonder if something could be "taken-out" (a motor or shim or something) to give me another 10mm of drop. I'm only 5'9 in trainers too so I'm only average height! Switching to a manual adjuster would be good if it could give me this little extra.
Cheers