Flux is far from redundant. Night Shift is horrid in comparison.
I'd be super careful about "converters." As a video editor, I'd like to point out a lot of convertors are not container changers, but compressor changers. What we want, generally, is as close to lossless, that is no loss of quality, as possible. Things like AVI/MP4/MKV/MOV are CONTAINERS and not CODECS (compressors, like H264/MPEG2/AVHCD/HuffYUV/etc). Most of these Container2Container type converters don't just change from "AVI2MP4" they re-encode, that is to say, they RECOMPRESS. Compressing lossy video which is already lossy compressed is bad. If possible, it's always best to merely change containers, assuming the codec is already one you're happy with. If that isn't possible, it's better to convert lossy video to lossless and then re-encode to lossy video. It's better than going lossy to lossy.