A mixer is best used for recording vocals over making beats in FL, unless you're importing sounds from let's say a Motif. It gives you better control over the lows & highs and input & output gain. I have a mixer and a midi controller but never use my mixer in FL besides overall volume control for my monitors. But like P. Casso said about the faders....I use my midi controller for everything in FL, from the play/record buttons to the faders that control FL's mixer. So to answer your question....No. It really has no purpose as far as your creativity goes, but still nice to have for recording vocals.