FF, what operating system are you on?
I, too, do single folder installations (two of them) and I have had no problems with resolution reset at all, as in never. One of my installations goes to full-screen and the other goes to windowed mode and neither of them gets messed around with.
My shortcuts all reference ryzom_client_r.exe.
I am normally in Windows 10, but I do have a Linux setup (also single folder) that has been patched many times without problems. Both systems have NVIDIA graphics.
I am not trying to minimize your problem -- I would be irritated at the symptoms you describe -- but I don't understand why you have it and many other people don't.
I'm on Win 7 Pro for all boxes. After patch, it falls back to a default resolution. If you usae that default resolution then you won't see the behavior. It's a known issue; there was a patch yesterday / today ... and unless it was an April Fool's joke, it's been fixed. See 1st item below.