Can't get >60Hz with MacBook Air M1 and 180Hz 5k2k Samsung Monitor

[lewismoss]

I have a Samsung G75F (5k2k 180hz).

I am currently running with the virtual display function, to be able to get better scaling (currently using 3584x1512). However, I seem to be unable to get higher than 60 Hz. As seen in the screenshots, I have access to higher refresh rates under the virtual display settings, but changing these seems to do nothing, presumably because under the actual display, the only available refresh rate is 60 Hz.

Please do ask if you need more information to help me diagnose; I wasn't sure exactly what to provide.

[waydabber]

I don't think in practice things work well beyond 60Hz with mirrored virtual screens.