I was wondering if an 2017 iMac can deliver power through Thunderbolt 3 (USB-C) ports to a MacBook (Pro) for charging, just like what a LG 5K Thunderbolt 3 display can do. I did not find any specs from Apple knowlege base. Does anyone know about this? Also, out of curiousity, what is the maximum watt that a Thunderbolt 3 port can deliver? Thanks a lot.