If you're passing a 1GB binary to base64 you're ... incredibly unlikely to be dealing with the resulting base64 manually (copypaste, text editor, whatever). So,

If you're passing a 1GB binary to base64 you're ... incredibly unlikely to be dealing with the resulting base64 manually (copypaste, text editor, whatever). So, yes, the expected default would still be no linebreaks. The primary purpose of these tools have changed over time as the environment has changed. You know nobody uses usenet anymore, and nobody copypastes base64 into emails anymore, right?