What do flat Earthers think causes the "magical downward force"?

The trouble with (1), (2) and (3) is that these cannot explain why the force of gravity varies with height above sea level…less at the tops of mountains - more in valleys.

If (2) was the case - then the acceleration would have to be EXACTLY the same everywhere - and it’s not.

1. Gravity is real - but the Earth’s disk is very thick so the force is very nearly vertical.

Unannounced And Petty: Southwest Fired Their Skycaps, Now Charges $3 To Check Bags At The Curb—After Saying They Wouldn’t - View from the Wing

If (3) was the case - you’d have the same problems as (1) - but this weir...

4. Gravity doesn’t exist - things are held down by air pressure.

3. Gravity doesn’t exist - it’s a form of magnetism that works on non-metals.

FDA Gives Tomato Recall Over Salmonella Highest Risk Warning - TODAY.com

If (1) was the case - the center of gravity of the Earth would have to be so deep down to avoid gravity pointing off at an angle when moving towards the “rim” of the flat earth that the difference in height of a mountain would be negligible and we would get very, very nearly the same gravity everywhere.

I have heard them say:

…and there are probably other ideas out there.

What are some healthy ways to start losing weight without risking starvation mode or extreme food restriction?

2. Gravity does not exist - the Earth is accelerating upwards at 9.8 m/s2 which seems like gravity.

They don’t know - and not all of them agree that there is a “magical downward force”.