Temporarily return External Layouts?

I’m making an arcade racing game, using external layouts for different borders that link up with the ‘main’ layout of the track.

How do I temporarily bring that external layout BACK into the main one to edit wall positioning? At the moment I’m copy-pasting the track walls back into the main one, editing them, then re-exporting to an external layout once I’m happy with it (which usually changes afterwards…).

I’m not sure if this is even possible honestly, but I thought I’d check with you smart folks.

Im not sure i understand your question
External layouts are like different scenes
There is nothing you can do in one scene to affect another (in editor)

Its like you make painting and you save it as MyImage.png
And then you use same image to create another image like MyImage2.png
Even so 2 is copy of 1st one they are separate and won’t affect each other

Or do you mean how to open external layout in editor to edit it?
Cause that you do from side panel on the left you double click external layout you want to open

If im understanding this correctly (which is seldom the case) then you’re wanting to line up what you’ve got in external layouts on the main scene. A method that ive used before is to take screen shots of your external layouts. get all these images the same size in photoshop. Create an object in the main scene with an animation for each screenshot image and bring it onto the editor. Position all the layouts. You can now create the layouts at the position of this object when needed