Charger 2 install and power station connection

I have an Elite 200 V2 and got the Charger 1 to 2 upgrade. I’m about to start the Charger 2 install and I realized that I didn’t consider all logistics. My current 4runner configuration has the Elite 200 V2 set away from the Charger 1, utilizing most of the length of the DC input (split 2/inputs) that came with the Charger 1. Config: Charger 1 on drivers side rear molle, then a fridge on a slide, then the Elite 200 V2 to the right of the fridge (kind of in the middle/right of the rear cargo area for easy access) The C1 cable is much longer than the DC input cable (XT60?) that came with the Charger 2, but it has the split inputs (4 MC4 connectors - for the solar panels and the C1)…

Questions: 1) Is it okay to use the split cable from the Charger 1 for the Elite to Charger 2 connection and just leave the 2 unused connections open? 2) There are longer cable options available, but I can’t determine if the cable needs to be rated for a specific amp. Is this something that I need to know? 3) Any other ideas/suggestions?

Thanks