Well, I bought one of these and initially loved it until I started scanning night shots with deep shadows (thin density areas). It revealed that the light source is very uneven and cannot fully cover 35mm, leaving orange haze at the edges. I tried a zillion tests to confirm it was a problem with the light source, and the head of Valoi agreed, sending me a replacement light source (it’s a Vijim video light). After testing that, I found the same problem, and at this point Valoi was out of suggestions, basically claiming it was as good as it gets and that it is the fault of the negs I used as examples (!!!).
So my conclusion is that this is a flawed design that is fine for casual work, but for serious scans, especially thin negs or night shots/flash shots with black backgrounds, you need to remove the light source and hold a better one up against the back (Viltrox works well for me). It’s weird to have to do a workaround like this on such an expensive item, but I’m not going to return it because of the speed and convenience of the film holder part. But I must say, I do feel a bit ripped off. I hope they get some competition for this type of product soon.