My real problem with using root user in my scenario is having to use node-gyp to build my repo. If you run npm install under root it can cause node-gyp to silently fail to build. The work around I found around this was to use this:
npm install --unsafe-perm
That got me moving forward but trying to have a consistent build from development, drone and into dockerhub is something I would like to achieve.
The challenge is that we use Docker volumes for the build workspace (where you code is cloned) and that volume is owned by root. As a result, if you try to access the cloned code as a non-root user you will get permission error messages. For this reason, the user field is ignored.