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.

I have heard them say:

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

How do military families handle communication when a service member is injured overseas?

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

…and there are probably other ideas out there.

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

Drinking this amount of water per day helps control blood sugar levels in people with diabetes - Earth.com

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

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

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

Astronomers discover black hole ripping a star apart inside a galactic collision. 'It is a peculiar event' - Yahoo

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

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.