I saw that one and suppose that is the answer to my question, how the folder is shared for both simulators.
The folder is supposed to be shared by the two simulators, which of course is correct, because it would be an useless duplication of data if you had to copy the same profile for the same airport installed in both sims.
But, if the airport is not exactly the same, or you have versions made by different developers of the same airport in 2020 vs 2024, the
MSFS-2020/2024 only setting explained at Page 47 of the manual, would tell GSX to load that profile only in one version of the simulator, so you have the best of both worlds: not having to unnecessarily duplicate data (with the annoying extra maintenance of having to keep the same file updated in two folders), but you still have the ability to isolate a profile for a specific sim, if it's needed.