Yes, filling the front bag cleans up the wake at slower speeds. Don't use any rear ballast, and set your wakeplate all the way down.
Weight in the bow keeps the bow down at slower speeds when it would normally want to rise too much. When the boat is running flat you get longer rampier wakes. When the boat is at more of an angle you get steeper more abrupt wakes and the foam at the top shows up earlier.
I tow my 11 year old on her slalom ski at 18 mph which would normally be a huge wake but she feels safe at the slow speed and the wake is so smooth she just rides up easily. It's more comfortable for her to ride with the bow ballast and slower speed than with less weight at a higher speed. My 8 year old spends most of his time boarding at about 14 mph. People up front helps too. It does make you pay close attention to the bow when you cross rollers going slow though.