They are all centralized exchanges, they can ask for KYC at anytime.

I use Huobi global and OKX among all.

I was unable to access Huobi global derivative trading until I did KYC. Maybe this has changed

On OKY, i was able to use derivative trading, and able to withdraw to certain amount. I left the exchange for like a month or two. When I go back to the exchange, i deposited some amount of bitcoin. I converted it to USDT. A time came when I wanted to move the USDT to another address, i was asked to verified my mobile number. I was unable to withdraw until I was able to verify my mobile number. I wanted to create a thread about this some months ago when it happened, but i just think it is not necessary because it is still a centralized exchange.

People should know that using centralized exchange can come with some inconveniences like freezing of your coins and blocking of your account. But even if this is not the main discussion of today, the there is still the fact that they can freeze your account and demand for KYC.