It depends on what you are trying to get out of the builder pattern. I think it wouldn't provide any benefit to you but hard to say without knowing exactly what you want to achieve.
e.g. if you want to remove all the stuff that you aren't using then nix already does that with a GC
```
FROM nixery.dev/shell/git/node14/python3.8 as debug_extras
FROM our/production:1.2.3
COPY --from=debug_extras /nixstuff /ubuntu/stuff
RUN python -c "print('nice!')"
```