I want to ensure that the development environment to work just the same as the production environment. This is to minimise \"it works for me\" finger-pointing.
You need to set up a custom platform then tell Elastic Beanstalk to use that platform at creation with eb create -p YourPlatformARN.
To confirm, within the linked docs, Ubuntu is supported through their custom platform service: "... the supported operating systems—Ubuntu, RHEL, or Amazon Linux ..."