If you had the money, which experiment would you perform to test geocentrism?

I would repeat the Michelson-Morley experiment, and I would also do the Michelson-Gale experiment of 1925, which has only been done once. Michelson-Gale used the same principle of light-wave interference as Michelson-Morley in 1887, except the equipment was oriented in a rectangle on the surface of the earth to measure rotation rather than revolution. The 1887 experiment measuring the earth's revolution got essentially zero, as if the earth were not moving through space. But the 1925 experiment, using the same light-interference principle to measure the rotation, got 98 percent of the expected result for the 23-hour-56-minute-4.09-second daily rotation, which is almost unheard of in experimental physics. That is devastating for heliocentrism, because heliocentrism must have both a revolution and a rotation; if you get nothing for the revolution but nearly everything for the rotation, the theory is falsified. In geocentrism we do not need a revolution, only a rotation, and it is not the earth rotating but the universe rotating around the fixed earth, which gives the same result.