Supporting QA-Environment: Setting different build & run time environment variables for different preview deployments

[ghost]

When Vercel is being integrated with GitHub, different environment variables can be specified per Git branch: https://vercel.com/changelog/environments-variables-per-git-branch

When using the BetaHuhn/deploy-to-vercel-action, I can add build environment variables, but as far as I understand they are not used during run time on Vercel. Instead the regular Vercel preview environment variables will be applied.

As I am following the Gitflow Workflow, I am looking into a solution how to define different environment variables for a release-branch to connect with a QA-Environment (Database, 3rd party providers and alike). Is there any possibilty to achieve that with BetaHuhn/deploy-to-vercel-action or do I need to switch to the Vercel GitHub integration. Any ideas and suggestions are welcome!