Do branches include env variables?

I've released my first alpha version and would like to keep my dev site separate. As such I've got 2 different URLs for redirecting magic link.

Would a branch allow me to set new env vars?

I know I could just clone the workspace.

Or it looks like I can just rebuild the magic link redirect entry in the function to pull from the $request_uri env variable? (I'm leaning this way, but the whole point of spinning up a separate release site for testing was NOT to break the site on the first day haha ... so maybe I'm back to a cloned workspace)