That’s exactly where confusion stems from.
Sketchup is a 3D modeller and it’s organization is object based, not layer based.
The way you structure your model is explicit in the Outliner not in the Layers panel. You have an organization that is: model > object > subobject > subobject > etc…
Objects in Sketchup are Groups or Components.
It’s how you organize a Sketchup model, where in a CAD drawing you split in Layers.
Therefore, thinking on style by Layer/Tag is never the right way as it serves only some purposes. If tags are there it is a viable option for some work, but not for all work.
My proposal is exactly to style 3d objects individually not tag based. You have a group that want to show in a certain way, in a certain scene then you style it that way. You just have to find smart ways to select the groups you need or several groups at the same time, and apply the style you need on the scene you are working on and save that to scene.
Send the scene to layout and the viewport will display exactly what you see in Sketchup. If you then want to override the linetype of some layer, you can, but it wouldn’t be needed if the scene was already as you wanted.
The problem is that styles work not per object, but per scene. All objects in the scene must follow the current style’s rules. You will only be free from that if each object can be styled different in a single scene.
Layers should could also change style by scene. It would work exactly as in Layout, but you would do it in Sketchup. This would mean that a dashed layer in one scene could be dotted in the next scene. A red layer in one scene, could be blue in the next. This would affect not only edges, but also faces but remember that this is a property of styles. It’s in Sketchup styles that you activate dashes, or color by layer. The problem is that you either activate color by layer and dashes for all objects, or for none.
Which means that if you ever want to present a window dashed in Sketchup, you have to make that window’s layer dashed, and you must activate all dashes on the current style, so all things in the scene will either be activelly dashed or not. You cannot have a specific object dashed while the others are solid.
It’s very limiting.
Why should we only be able to do that in Layout doesn’t make sense for me.
And that’s why we should be able to style objects by scene differently and not all objects in the scene with the same rules.
That’s what could give us creative freedom and freedom from Layout+Sketchup’s speed, workflow and style limitations.
Sometimes overriding line styles is good enough, but the full solution in Sketchup would be to have all of Sketchup’s output empowered, not only Layout and not with limitations.