Re: So, to sum up. . .
You can have as many referendums as you like, so long as it's clear what the options are.
In 2016, the "remain" option was clear, but the "leave" option was not well defined. (Many people say it was deliberately obfuscated. I'm not taking a position on that, but it is undeniable that the "leave" campaign did not advocate, then, for anything even remotely like what they're advocating for now.) That needs to be rectified if that is to be held up as the definitive democratic verdict.