applesandrice said:
However, after de-muxing the MKVs and importing the video and audio streams, Encore still requires that the video be transcoded.
It's easy enough to create menu-free BDs using tsmuxergui, which is what I do. Some authoring tools simply don't let you do anything without a transcoding step, and I'm not sure it's avoidable, other than using different tools. There may be other tools out there that allow you to create menus without transcoding.