Removing ability to create guest users on Xiaomi Tab 6

I own a Xiaomi Tab 6 with Android 14 (Xiaomi "HyperOS" 2.0.6), and with have enabled multi-user support by disabling the "MUI Optimizations" as described in various online forums to be able to create true Android user accounts compatible with Google Family Link. I have set up two such accounts for my kids and this works fine so far. However, there is one catch: enabling multi-user support also seems to enable the Guest Mode support which - in the Settings app - enables every user (also Family Link accounts) to create a guest user which is not under Family Link control. How do I remove this option from the settings, and/or prevent the creation of Guest users altogether, preferably without having to root the device? The guest_mode_enable toggle you can set using adb seems to have no effect (when multi-user support is enabled).