FYI, you may already have seen this, but Fosi has this to say regarding the amps performance with the different power supplies:
Based on our measurement, using a 48V/10A power supply does not significantly increase power output compared to a 48V/5A power supply. Other parameters, such as signal-to-noise ratio, THD, and frequency response, are also virtually identical. Therefore, there is no noticeable difference between the two options in terms of your user experience. We are offering this one-to-two power configuration option for more flexible system building. Of course, by using one less power supply unit, you can save space and achieve a neater system setup.