Using different wallet for gambling and savings is indeed good but it doesn’t increase the security of your account you are just using different wallet. It only minimize your losses when your account was hack.
I think 2FA and SMS verification are already enough safety precautions for securing casino account. We usually don’t leave balance on our casino account so I don’t see this security concerns as major concern. I’m gambling since 2016 via online casino and I didn’t experience even a single case that my is hacked. I don’t use any extra security aside from my password on my account.
Our casino account will be safe if you don’t login from links provided by other user. Always bookmark the official website and you will be safe even without this extra security.
I do the same as you and keep my balances small on casino sites but there are a lot of members with high balances on there (over 1000$ and a lot more). I do 2FA for every casino as we have had multiple cases on this forum where accounts got hacked so I would be carefull. It is not because it hasn’t happened to you, that it can’t happen so I would always add 2FA to my accounts.