Can I reuse the work I've done to develop Redwood UI in other environments?

Yes. The build process packages and deploys the code from GIT to the target environment. A best practice is to have one branch for each environment. For example, you can have a main branch for your primary development or test environments, and a production branch for the production environment. Additional environments can have their own branches. You can merge the code into a release-level branch, and then do a build from that branch to deploy to the environment.

For details, see the Oracle Cloud Administering Visual Builder Studio guide.