Is there a way to copy zones that were defined in a clip and inserted into the project bin from one Kdenlive project to another ?

The only way it could work: set in/out in project monitor -> right click -> extract zone -> you get a file which you can use in another Kdenlive project.

Ok, thanks. Do you know if there's any plan to implement a simple copy-paste between 2 Kdenlive instances or import an entire project bin from another kdenlive file?