Suggestion: to change a calculation of rating changes when berserk used

Rating has to reflect the chess strength of players. But berserk game is similar to game with leg-up, so when berserk is used, the calculation of rating changes should be changed or annuled at all. You may say it's a risk of the player who uses berserk, but I say that the player who uses berserk is not the only one who suffers. When he reduces his rating due to some berserk games, after that when he plays regular games, his opponents lose points because of his lower rating. And this is not fair.

What would be unfair is having a button to let a player avoid losing rating points.

Sorry, but I don't understand your response. My rating in blitz is 2100 roughly. When I play berserk in blitz, I can reduce my rating to 1900 or even more. It's not a problem for me because I'll return it later, but when I play with other players and win them, they lose more points in comparison with the situation when I don't play berserk and don't lose points. This is unfair with respect to these players, because they think they play with 1900, but really they play with 2100.