Also, how do people do HD releases these days? Just a standard MKV or MP4 file, or do people do full on blu-ray authoring?
Please do both if you can! MKV is good for convenience but Blu-Ray is still better for quality (in my opinion) due to the way most new players (oppo 203/Panasonic ub-9000, I use the latter) handle upscaling of hd content on a blu ray. Team negative 1 does both for projects like 4k77 (they release an mkv and an HD blu ray) and honestly I prefer it that way. And plus, who doesn’t love the menus!