That's a slightly different issue. I don't think people consider visibility attributes under the rubric of safety, usually, except in sandboxed contexts. That'

That's a slightly different issue. I don't think people consider visibility attributes under the rubric of safety, usually, except in sandboxed contexts. That's more a problem of build tooling. It should be possible to modify visibility/finality levels in libraries as you download them. Gradle can do something like this with some work, but someone should make a plugin to automate it. That way the upstream can set things private/final/sealed as correct for their API guarantees and design, and downstream can apply hacks to open things up if that's easier than forking the source code, and there's a single place in the build system that collects all the places where there's a mismatch.