but I see the comment from another user that this URL is down from days ago.
You mean the comment written 2 hours before yours? Nothing was down before the maintenance.
mmm cold wallet seems solid... this gives a little bit of trust but I would like to see movement or signing of messages to be sure.
It would be fairly obvious to claim an address they do not control as cold wallet, for over 2 years.
I guarantee you someone would have noticed that very quickly.
BCH distributions were made from the cold wallets, so any investor with a bigger sum invested can verify this.