Sharing a KMS device

[Troll Berserker]

In DRM, only one application can be drmMaster at a time.
This is one of the reasons why one can't run a Xorg server per Connector to have multiseat with one GPU.

Is it theoretically possible to implement a driver (let's call it shared-modesetting) which will offload mode setting to a helper daemon (drmMaster) thus allowing to run multiple Xorg servers on one DRM device? (provided that there are enough CRTCs (?) available).