For the Multi-core cable, software is showing the 240 or 300 mm2 conductor as a maximum cross sectional area result.
This restriction is due to the IEC standard. You can see from below reference;
But with My Ecodial L 3.4 it will be possible to pass besides this limitation during the software adaptation.
Moreover in many countries you can not find any multi core cable beyond 300 mm² CSA.