Sorry @afre this is really bad, not only hijacking again but avoiding your question! I doubt I can answer it well in any case since I avoid colour space issues as much as possible 
@David_Tschumperle
I’ve been looking at poisson disc noise and one of the first things a search returns is this paper coupled with this example public domain source code in c++, both of which look really quite simple (honestly!). Simple enough that I might even attempt in g’mic, but it does use lists/arrays with removable elements which I think might be awkward in gmic.
On to the question: is there already something in gmic for poisson disc noise and if not is there a good way to implement it? What are the chances of it being added to cimg?
Edit: I think now this might not be the type of “break” you were looking for!