Thanks, I think it's starting to make sense now. Based on that I settled for the below settings. From X=0 Y=0 I can basically travel to a max of X190 Y180 which then covers my build area and due to the FRONT_PROBE_BED_POSITION I can't probe any closer to the front edge.
// Travel limits after homing (units are in mm)
// Set the boundaries for probing (where the probe can reach).
#define RIGHT_PROBE_BED_POSITION 180
#define BACK_PROBE_BED_POSITION 180
#define FRONT_PROBE_BED_POSITION 40