Regarding the live chat agent asking the customer to upload their information, I have not experienced it at a casino, but I had that same experience with a CEX. After several failed KYCs, I contacted the live chat agent and was asked to upload my details to them.
Didn't experience that scenario since I always go to the right channel performing those KYC process that they asked me to do. And for me its bit weird for being asked to upload it on the chat box since its like I don't feel any safe to do it especially that possibly a lot of people who handle on their support side that can able to see those details. Unlike if we are doing it on right place maybe there are only less people could able to see it(If I'm not wrong with my assumptions here).
But if I experience that situation on CEX then maybe I will not comply to that situation they asked me to do and will transfer to another exchange where everything is fine then can able to do KYC without having any further issues.
It must not have been safe to do so, but I actually did it some years ago, and then I was not really too informed about the risk that is related to giving out personal information so freely without minding the outcome. That's why I said that the reason some people make mistakes is due to a lack of proper information. It was after I joined the forum that I properly understood the dangers of KYC.