Pretty sure that raw video (.crm / .ari, let alone Prores Raw ) is not ISO invariant.ALWAYS use an external monitor, like the mentioned ninja V, which is also an external recorder using ssd drives.
I guess you know what RAW is. It's the same as RAW in photography. It allows you to shoot "iso-less". You can change your exposure (ISO) and also the color temperature AFTER you shot your video, in the post.