If anyone wants to know what looking at an Animal or some objects on LSD is like, this is very close. It's like 95% understandable, but that last 5% really odd.
It was pretty important to work with the Project Managers and "scrum-masters" to decouple our release cycle from our sprint cycle. In our case, like yours, they were coupled together for no technical reason. It's hard to sum up all the changes we made to allow it to happen, but mostly it boiled down to a few technical decisions -
* Every PR is treated as "production" ready. This means if it isn't ready for user eyes, it gets feature flagged or dark shipped. Engineers have to assume their commit will go into prod right away. Feature flags become pretty important
* Product Owners and QA validate code is "done" in lower environments (acceptance or staging, or even locally during PR phase). This helped us decouple code being in prod and "definition of done" in our sprints.
* All API changes and migrations follow "expand and contract" models that makes the code shippable. e.g. even if we are building new features, we can ship our code at anytime cause the public api is only expanding.
* More automated quality checks at PR time. Unit tests, integration tests, danger rules, etc. These vary from codebase to codebase. A key part of this is trusting the owners of that code or service. To a degree, if they are happy with their coverage, then they can ship. (Within limits of course. Not having unit tests at least would be a red flag)
Also, we still ship numerous times a day without a full automation test, we just make sure each release is really small (1-3) commits. The smaller the release the easier it is to manually QA it. So nothing fancy is needed, just smaller releases.
So to answer your question, we don't pick and choose work that is "low" impact or "high" impact, all code gets shipped the same and with the same cadence. It is our responsibility to ensure that when it goes to prod, it won't break anything
One of the hardest challenges I have had in my career is convincing our company to move to Continuous Delivery. 90% of the challenges weren't technical, but emotional. Shipping software comes with lots of feelings, fear, politics, etc. I had to personally work with various leaders across the org to help them through these feelings and perceived blockers.
We aren't 100% there yet, but we are shipping numerous times per day across 20 or so services and quality has gone _up_, not down