Google Safe Browsing looks to be have been built without consideration for open-source or self-hosted software.

IMO Google Save Browsing was built with consideration for open-source and self-hosted software, but it has nothing to do with user safety, just like blocking Android apps from 3rd party sites has nothing to do with user safety. The harder they make it to move away from their products by making using alternatives difficult, the more money they make and money is now the only objective. Even if this only adds a fraction of a fraction of a percent to their profit it’s something Google will implement.

The old social contract of businesses being of benefit to the community as a whole in addition to making a profit is long gone.