Limit FPS when game has fixed FPS setting

Hello, I have game that supports Steam lobbies. Since there will be a situation where player has terrible FPS, i want client to know when server has terrible FPS. Let’s say client connects to the server that has 30 FPS only, but client has strong PC that has 60 FPS. How do I tell the client to lower the FPS to 30?

Please note that GetGameUserSettings::SetFrameRateLimit does not work when there is fixed FPS setting. At least it does not work for me. Same goes for console command. Is there another way?