How to scale a MeshInstance3D AND a PhysicsBody3D at once?

[undone nest]

Sidenote: I know that CSGs are preferred when it comes to prototyping, but id like to know the method when it comes to actual deployable development.
I am a total beginner, and the way I create objects currently is that I create a StaticBody3D, then I add a CollisionShape3D and a MeshInstance3D to it. This works well, however the problem is that when I wanna scale the object (let's say I wanna make it twice as wide), I have to change the property in both the StaticBody AND the MeshInstance. Is there any way to bind the two values together? Or am I doing the whole thing wrong entirely and there's a better way to do it?

[thorny wave]

If the MeshInstance3D a child of the PhysicsBody3D, it will follow its scale.

Unless there is a non-3D node as intermediary between the parent and the child.

The node will also ignore the inherited transform if it has its "top_level" property set to true.

[undone nest]

i have it set up like this, and if i try to change the scale of the StaticBody3D it gives me a warning saying it wont function as expected with a non-uniform scale

it says "change its size in child nodes instead", and since the two children can only be siblings, i cant figure out a way to bind them

[thorny wave]

Yeah, PhysicsBody need uniform shapes.
And you can't scale CollisionShapes at all.

[undone nest]

sorry i meant scaling the shape of the CollisionShape, this here

[thorny wave]

Generally you don't want to have a 1:1 between your visible mesh and your physical mesh. Since one is more expensive than the other.
But if you do want that, you'd have to make the shape trough code to have the same points as the other shape.

Altho BoxShape does not actually use points.

[undone nest]

so generally ppl just change both variables every time?