I would say playing fretless at home has helped with my fretted playing.
First off, I have to say that I'm not up to gigging standard on fretless but getting used to playing at home, on my unlined fretless and really listening, as opposed to looking at my fingers, has proved invaluable for when gigging my fretted basses. It has helped for example if the stage is dark, or I've been blinded momentarily by the stage lights and also I don't need to spend the whole gig looking at the fretboard