I think the idea of a “minimum valid test” is really what you should be aiming for. There should be a private phase for usability and to see whether that quest

I think the idea of a “minimum valid test” is really what you should be aiming for. There should be a private phase for usability and to see whether that question can accurately be tested. Your goal is to make sure that your terrible site design or code or whatever does not get in the way of the test. Then there should be a scaling phase, some call beta. You can create scarcity by doing beta password signups to make sure that your servers aren't causing users to not enjoy the site (why is it so slow?!). Then, I think it's the public phase, where you let anyone come to your site. Really, if you have courage and trust in your abilities. going straight to public is the best option because it causes you to iterate quickly.