It's probably going to depend on what you mean by 'the phenomenon'. Do you mean that the sun casts shadows at different angles at the same time of day based on your location? Then yes, it absolutely does. In fact some believers in the flat earth theory use the experiment to establish the distance of the sun from the earth.

If you mean something else, then I have no idea. I'm not a proponent of the flat earth theory, nor am I a mind reader.

The experiment you proposed does not disprove the theory of a flat earth though, parsimoniously or otherwise.

It sounds like you may have rejected the notion of a flat earth purely on faith after all?