Input 4k HMDI Signal to ATEM MINI Extreme from BM Studio

So I have 4 Blackmagic Studio Camera 4k Plus G2's and the ATEM MINI ISO Extreme HDMI edition. I would like to send 4K signals to the switcher. I hear that people are saying that they can send 4k signals to their ATEM Minis and the unit will downscale the signal to 1080p, this being done with "non-Blackmagic Cameras" however. The video quality is much better, which is why I want to do it.

How can I do this with my Blackmagic Cameras? Is there a way to bypass this feature? Why does Blackmagic lock the camera to 1080p when connected to an ATEM Mini and not allow one to send the 4K signal for downscaling? Please Help!