If you use the 2-wire configuration then the resistance of the wires affects the temperature readings. AFAIR the reading increases by 0.4C per ohm of resistance. If you use the 4-wire configuration then the resistance of the wires gets cancelled out. That's the only difference.
The two "jumper for 2 wire" spots are already connected. They only need to be broken if you are using a 4-wire connection and a 4-wire PT100 cartridge.