Uhm, well. I gues you want something like shown in the second screenshot of the first post. This is done with the instance specific **Debugwidget_PrintString **node. Drag of a DebugWidget instance variable and search for “print string” again. That will print only to that specific instance.
As far as I understand it you have a single BP that has multiple static meshes (or instanced static) that are spawned dynamically. In that case you would need to spawn a DebugWidgetComponent for each spawned static mesh and attach it. It would be easier to handle if one blueprint spawns multiple other blueprints.