Currently there is no setting to change the brake disc so it would be good to have the ability to change the brake discs in the game between ceramic and steel brake discs. If there was a noticeable difference in braking power and effort needed to brake then it would be an awesome feat for the game.
first of all titanium will be the brake disc of the future not ceramic... second no one in real life changes their disc you just have what you have and since we all have the same one anyways I think that's fine as long as it feels real...
There is almost no difference in the way it feels, the only real advantage is the lower rotating mass. I definitely wouldn't say no one changes their disc, I know lots of people who aren't running standard discs in their karts.
In america we arent even allowed to run ceramic in most series...