AFAIK, there's no way to avoid those opponents that you may face if there's gambling on it. They are there to make money and will cheat to have a sure win and get your money as well.
I guess the best way which was suggested in the last pages is about having a dual cam like making it a requirement for those participants, first is with showing them what it looks like whole body and back shot. But if we're going to analyze it, it can still be cheated and they could just give some recording of them sitting there and does show as actual footage and not suspicious video of them just like what we watch in movies.
It's hard to prevent cheaters on online chess, at least on short run. But as far as I know, there aren't perfect crimes and sooner or later users using third party services to compete online are going to be busted and have their access to the platforms restricted (at least serious platforms).
I say that because it happened to a very popular youtuber from my country. It was a scandal where he was severely criticized on the internet, being his final attempt to create excuses he wasn't using bots, but having assistance from a "teacher" in real time, instead.
Mechanisms like KYC and forbidding recent created accounts to play competitively could highly weak cheats on this game.
For sure there will be ways of avoiding it so that these abusers will never find a loophole that they can take advantage of. About KYC, I think even there is a kyc, they can still abuse and cheat if they have to if it's going to rake them a huge amount of money. These people really have intention to cheat as long as they get a huge profit from that. But it's true that it could lessen the potential cheating but still, there's still ways for them to find it out if they've been born to be as a cheater. Right now, there are no platforms that can guarantee it and there's no casino yet that's interested of putting this up.