Instancing a Node with Unique/Unlinked resources

[vonflyhighace2]

Godot version:
Any

OS/device including version:
Any

Issue description:
Whether you duplicate or instance an object its resources are always linked back to the original node/scene. This means that technically you never really get a 100% unique object. This is a problem because if you wanted to tweak the object at run-time you basically have to hack together something every time to further duplicate/unlink the resources, which doesn't always work either at that. Having

Steps to reproduce:
Having the ability to create a complete copy and not just a half referenced clone really is a must have feature. I can't think of a reason why you won't want this functionality. maybe an extra parameter in the "instance" method to specify a complete copy?

Minimal reproduction project:
There might be another similar thread but not sure about it.

[LinuxUserGD]

Take a look at
https://github.com/HugeGameArtGD/Solus-Stunts/blob/95b4beaad498732e57d4ea231731e0b18fed78d7/source/car/car.gd
It's possible to create a new ressource (e. g. Spatial Material) and assign values to it. This ressource is unique and can be applied to the object.

[vnen]

Looks the same as #1213.

[vonflyhighace2]

That thread seem to talk about duplicating an existing node in the tree. I on the other hand want a 100% on-tethered copy of an instanced/packedScene. Different context I suppose.

[Calinou]

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