I don't think that "fill banks" is what you are looking for (that was something more specific to the issue I was seeing). What you guys would be looking for is banking appropriate amounts of banks for the amount of control surfaces that are setup, (i.e. DM3200 users would want 16 banks aka 2 controllers, DM4800 users would want 24 banks aka 3 controllers).
Fill banks would do things like if you had channels 1-17 used on a 16 channel controller and you push bank right with "fill banks enabled" you would then see ch 2-17 (where as with proper banking you would see 1-16 and then 17-32 when banking).