I don't think we want a was
If it’s difficult to keep up with current affairs, imagine to form an opinion about something that happened 30 years ago. (Oh, the curse of year ‘*9.) If they are protesting for Lam’s resignation, it’s still not too late for Beijing to take a step down; if as they say they are demanding free election, no way it will happen under Xi and it’s anyone’s guess how it will all end. My opinion is that they badly need someone (all the ex chief executives and also nonpolitical figures) whom both sides trust, just like some Republican elders need to come out and stop/rein in Trump. Both are unlikely to happen.
If all this happened back in 2015/16 when the bookshop keepers were taken, it would have been a clearer if not stronger message, and depending on the outcome the discontent/distrust might not have risen so high as it is now.
No. I'd want a referendum.
Scotland had a referendum on becoming independent. They chose to stay in the UK: https://en.wikipedia.org/wiki/2014_Scottish_independence_ref...
Britain had a referendum on leaving the EU. They chose to leave the EU: https://en.wikipedia.org/wiki/Brexit
So why not simplify everything and allow Hong Kong to hold a Chexit referendum? Let the people of Hong Kong decide what they want for themselves.