Menu class - multiple instances in panel (or way to pass a parameter) ??

excuse the misunderstanding
The problem is that VIEW3D_MT_master.bl_idname is one menu for all your layers
Yes blender make a distinction to build the panel but is the same menu.
You every end up with a menu that have the value for layer (i) that is the same for all
I continue to see if there is a solution but at the moment I don’t see nothing of useful
Using a variable that set the active layer…? But how to set this before to click on the menu…?

Yes exactly. The fix would be to have the menu() call return the instance of the menu just like the operation() call returns the instance of the operation.

Thanks.