If you make a change to whitelist the update will occur the next time that vulscan runs.
We do not have anything in the current build that can do an "auto" update but I have heard talks that this will be in future builds.. We will have to wait and see:)
What we currently do is to push a vulscan... it take about 5 seconds to get the updated config (first steps of the scan)... but the vulscan will take about an hour...
I want to add that our 9.6 agent has been revamped, and should be able to do this:)
We will know more closer to release, but good things are coming!
Thanks. Are we talking about 2014 ?