Don't worry, no bookmaker or anyone else will ban you for changing dns to 1.1.1.1 or 8.8.8.8 (google dns) or whatever else. This method just helps to access sites if your ISP block them, it's not hiding your real IP in anyway. Just make sure they allow citizens of your country to play.
In my coutry goverment banned access to all foreigh gamblings sites, but its still legal to play everywhere so I’m fine.