In a nutshell
1. create the detail in its own drawing then export it as a PNG file (Export Drawing As… command), usually to the project folder
2. insert that detail into any other drawing as a picture in paper space so that it doesn’t get rescaled with the drawing
3. use tools like Calibrate if you need the detail to scale or just use the Resize command if you don’t need it to scale
After you do this once it goes really fast.