> You make a prototype, try it at a small scale, make limited deployment, fix the problems, make it safer, and then deploy it more widely.
This makes an assumption: that the problematic technology is an intentional development rather than an emergent feature of an intentionally developed technology.
We already have a name for such emergent features: "bugs". No one really deployed Heartbleed, especially not in a limited deployment. Spectre? Rowhammer? And we all had/have to deal with the fallout, and we're not even done.
Who says that the danger of the technology cannot stay hidden until it's universally deployed?