The MHS11 Monitorius Stand Mount from ASUS is compatible with monitors that support the VESA 100 x 100 mm mounting standard and have a maximum size of 23.80 inches. Since the ASUS XG258Q is a 24.5-inch monitor and supports the VESA 100 x 100 mm mounting standard, it could theoretically fit, but the size slightly exceeds the recommended maximum size of the mount.

It is advisable to check the technical specifications of the monitor and the mount again to ensure that the mount can withstand the weight load of the monitor and fulfils all requirements.