As I understand atma-sphere (Ralph Karsten's) explanation, the lower your setting is, the stiffer the cantilever (& suspension) of your cartridge will get. The higher settings allow the cartridge to track more freely. I have found that many LOMC cartridges sound best at 47K ohms, even though that is the typical MM cartridge setting.
I'd suggest that you start off with the 47K ohm setting & move down from there. At 47K you may have a brightness or glare If your phono preamp doesn't have a stable circuit. Move to 1K if that is the case and work down. Ralph explains it much better. But I've used 47K for many years with little or no issue