Thanks alot for the great responses guys. Todd, so simply downscale/reframe the 2:1 4K files into the 1080 16:9 frame/sequence within premiere? I see what you’re saying, makes alot of sense.
Just a couple more questions, does scaling each file within premiere retain the quality better than transcoding the files would? And is there a good consistent way to scale the files down to the exact correct size and position within the frame?