Jonathan-pas again it comes down to speed and time. I actually work in the film and video industry also. If we are talking about working with and backing up large amounts of REDCODE footage, the way Unraid works you will have to either keep the server on at all times or update the speed of the array. It wont take super long to get the footage from the working SSD to the cache drives but at 5400RPM it will be an eternity to redistribute the footage from cache to array and then to sync up parity. But then again if you are primarily a photographer that is running like an a7sIII and occasionally doing video, or even if your video is REDCODE and its small form stuff for like Social Media, it wont be as bad.
My rig has multiple SSD for cache and 7200RPM HDD in the array. I work off the cache during the day and at night everything safely gets pushed to the array that is not on a Cache only drive.