I think the stronger point of what you're saying is if you can set yourself to avoid addiction—you have a time limited dose, you have no means of acquiring more—then opiate painkillers are the safest option in terms of potential damage to your body.

There's no avoiding it when it comes to some people's chronic pain but it's a tragedy we've ruined the reputation for opiate painkillers because they were prescribed for long periods which all but guarantees addiction. Folks in US hospitals have to unnecessarily suffer short term acute pain because squeamishness around prescribing effective painkillers in a situation where there's virtually no risk.