Everyone has a right to their own beliefs. I have flown around the world I am a builder by trade I have a lot of knowledge in weights, balances, math, measurements and geometry. I'm sorry but flat Earth just doesn't apply to any of my experience with theories and design.
Example: A project I worked on not long ago building a hospital close to the Bay. The foreman and superintendent could not understand why on a daily basis our datum point would change which is where we take our measurements from to build off of. I had to explain to them that building by a bay has tides come in and out that actually cause the land to rise and fall as the weight of the water is so immense that it changes the height of the datum points on a daily basis. Earth crust lays on top of liquid. You will also notice this during an earthquake which I have witnessed from a viewpoint during the 1989 California earthquake which you could actually see the seismic activity across the ground that looked like waves,