Features the Nvidia Linux driver is missing vs. others, please implement

Wayland specific:
-no GPU gamma ramps: Changing gamma/display calibration settings on Plasma/Gnome Wayland has no effect with Nvidia
-no custom EDID support: Also with activated kernel mode setting, the Nvidia driver ignores drm.edid_firmware kernel boot command
-Probably the same goes for variable refresh rate on Wayland, though I didn’t test this one

-no voltage access: On Windows, third party tools can alter boost clock/voltage curve. On Linux, there is no equivalent and thus you can’t undervolt cards (which is a real pity for Ampere cards with high power consumption). On Linux, the Nvidia driver only allows to decrease power target value, which is not the same.
-According to this thread VK_PRESENT_MODE_MAILBOX_KHR should work: VK_PRESENT_MODE_MAILBOX_KHR behaving incorrectly
But it causes flickering for me in at least Wine fullscreen applications with both latest 465 and 470 drivers (it can be forced via libstrangle or mangohud and works fine with other drivers), unlike fifo vsync. Bug or not fully implemented? This would also be important for Wayland, as there is no immediate mode for it yet and it is treated like mailbox instead.