Would everyone here be okay with
```
 *     As userspace can't currently know whether or not the output is using
 *     RGB or YCC signalling, the driver must translate properties to their
 *     relevant RGB or YCC counterparts, depending on the actually used
 *     signalling. Property values that are only valid for either YCC or RGB
 *     must not be exposed as supported, unless the driver can guarantee it
 *     never uses the signalling that doesn't match the property.
```
as documentation for the new behavior?