[orangeboats]

> If we want to move to a version with minimal privileges

Then you would have to cut everything provided by the X protocol into many, smaller, controllable pieces. Because if the permission control is just a switch that says "ability to communicate with the X server", then the whole exercise is rather moot, isn't it.

And when you cut the protocol into smaller pieces...

[uecker]

No, there is already a secure mode which in the past worked fine but was bit too restrictive for modern clients, and there already exist hooks for fine grained access control.