In all my years of printing, I've never used the red filters attached to many enlargers. I never quite saw the point.
They might come in handy for exposing more than one neg onto a piece of paper and one only has one enlarger. Or perhaps rechecking focus during exposure/burning. But they are a low-priority item for most people.
At least with LF landscape, a bad day of photography can still be a good day of exercise.