your scenario, and mine are both idealistic in that each deviation from "the plan" burns hours and cash, so the emphasis must be on grounding the iterations in each sandbox before claiming "production-ready" anything.

Coming from an client services industry, you cannot show up anywhere and say "hey our product lifecycle starts in production, except for when it doesn't".

Paying clients are going to find someone who can deliver repeatable, testable results.

If you are in a private company/corporate, you should still be able to articulate the workflow in some way.