Will there be any problem with using different motor tuning acceleration parameters for the X and Y axis. Just wonder if there would be strange results if, for example, cutting a circle at a high speed or if rounded corners would be asymmetric if Constant Velocity mode is used.

You can have different vel and accel on all axis if you like

Hood

your suspicion that CV will be asymetric is correct. However they have to be quite markedly different before I think you'd notice (depending on your accuracy requirements of course). Personally I prefer to have X and Y accel the same for this reason.