It’s basically an executable file designed to resemble, in its style, a DVD or Blu-ray.
If that’s the case, this seems…completely pointless. As in, I honestly don’t understand in any way how this idea is beneficial when you can just make an MKV or MP4. It’s not like aspect ratio or resolution are an issue with those formats.
Sorry, I’m really not trying to rain on your parade, I just…don’t get it. Do you just really want to be able to make, say, a 1.5K, 1.66:1 movie with a full menu and extras without having to conform to a BR or UHD-BR standard with letterboxing and upscaling/downscaling to a set resolution for some reason?