I know what MLAT is, have a basic understanding of how it works, but still don't understand what explicitely will change when telling VRS that a certain feed is MLAT.MLAT
This tick box is only enabled when you select a receiver in the Receivers list. Ticking this box tells VRS that the selected receiver is an MLAT feed. The feed calculates positions for aircraft that do not transmit positions themselves. VRS will use these positions even if the feed is not the nominated feed for an aircraft.