So did anyone watch the video?

Was their execution of the experiment valid?

Was the math that they used appropriate to the data collected.

The math made sense to me but was it applied properly?

Once you determine the angle A the rest of it is correct.

It works on both models, flat and globe.

Looking at that last diagram we can conclude that altitude calculation would be even more accurate on flat model.

The only thing that might be inaccurate would be the very first step, determining the angle A.

Now let's calculate for how much.

Angle A was determined as if the distance from Moon to ISS is equal to distance from Moon to obdservers on the ground.

The mentioned 0.52 degrees of the Moon is from the ground.

In globe model that ratio is 400 over 384 400, ISS is just about 0.1% closer and angular diameter of the Moon from ISS would be about 0.1% bigger.

Error in determining A would be about 0.1% and altitude of ISS would finally be 0.1% lower. (418.64 km instead of 419.06)

In flat model Moon would be 5005 km above the ground, which is 5005 / sin(53) = 6267 km from observers.

In that case ratio is 400 over 6267, ISS is 6% closer, Moon angular diameter from ISS 6% bigger, ISS 6% lower. (393.91 km instead of 419.06)

It is still 10-20 times higher than anything else, except for rocket gliders. ISS is "only" 4 times higher than they can reach.

Balloons can not move at even 10% of the ISS apparent speed across the sky.

Piston-driven and jet propelled aircraft would never be able to carry enough fuel to cover any possible location at any date and time where observers could decide to watch from.

Rocket propelled glider with 112 km is still based on rocket boost, not on air lift, and fuel consumption is even higher.

Altitude records:

hot-air-balloon - 21,290 m (69,850 ft)

helium balloon - 41,424 metres (135,906 ft)

piston-driven propeller monoplane (without a payload) - 18,552 m (60,866 ft)

electrically powered aircraft is 29,524 m (96,863 feet)

jet propelled aircraft - 37,650 metres (123,520 ft)

rocket propelled aircraft - 112,010 m (367,487 ft)

(from:

https://en.wikipedia.org/wiki/Flight_altitude_record)