Control keyboard LEDs from a background process

The ability for an unprivileged background process to control keyboard LEDs is a useful feature of X11 that is missing from Wayland. This means certain classes of tool either must have their functionality degraded under Wayland, or cannot be ported to it at all. For example, status indicators that use the Scroll Lock LED in order to be visible when full-screen applications are running, keyboard backlight auto-adjustment utilities, and site-specific scripts that use the xset led command.

The only ways I've found to control these LEDs on a Wayland desktop are the /sys/class/leds filesystem and evdev nodes. Both of these require granting special (and potentially dangerous) permissions to users, making them unsuitable replacements for what can already be done in X11.

(This issue came up for me recently because one of my own tools is affected, but a bit of web searching shows that it has been frustrating others as well.)

It would be nice if Wayland had a protocol for this.