Not actual experience. At some point in the past, I tried to register at casinos using Tor, but either access with Tor is blocked or it works so poorly that you can't do anything. With Duel, you can access it using Tor and even place bets, but it doesn't work 100% well; some games don't load. Better VPN, as you say. But the fact that you can somehow use Tor on Duel, I think, is another example of his commitment to privacy.
You're putting a lot of faith in their goodwill by calling it a 'commitment to privacy'. I see it as a liability they can weaponize against you..
I guarantee you'll find a clause about 'providing accurate information' or 'not attempting to circumvent our systems'.
They don't have to explicitly ban Tor or VPNs because those catch-all phrases are their escape hatch. Let's say you hit something big, a five-figure win.
They'll trigger a security review, see your connection logs are from a Tor exit node, and they have the perfect excuse.
They'll cite their own ToS, claim you were masking your location or engaging in 'suspicious activity', and just void your winnings... it goes both ways