It is dangerous to talk about resistance in Hong Kong now, publicly or even in private. As you mentioned, there are multiple layers and various tools being utilized in the surveillance. There are laws and regulations that encourage reporting of any suspicious speeches or acts. There's a culture of reporting each other for things that are not politically correct, and the authorities are encouraging that as well. It is getting so difficult that I don't see how the resistance can become organized.
There are certainly a lot of contentions and a lot of anger among people who have gone through the 2019-20 anti-extradition movement that turned into a democracy movement, but people cannot communicate openly about their feelings. I can't really see a turning point until people understand it is safe again for them to talk about it or express their political opinions openly. With the current repressive regime and more draconian laws coming, I really don't see that being on the horizon.