People should not use those things that might give them an issue that's why even if they are not bypassing restriction or whatever reason they have, better that we should not use VPN. So that they won't find anything suspicious on our account and with that we can also avoid any future problems.
This is true,it has already been stated on their TOS and if they give any slight chances others with negative intentions may see it as an opportunity to lie.
I also agree that mirror site is better to use if they experience difficulty of accessing their casino. But they should ask the link from their support so that they would get the exact link and not the scam came from random people online.
This is another method than going through their TOS and would be more less time consuming especially if the casino has as an efficient Customer service.