I downloaded trial versions of the two alleged Blu-ray authoring packages & unfortunately neither works with valid H.264 Blu-ray files created before AME messed up. Neither package recognises separate video & audio files but even worse the Leawo application comes up with an error when I import the video m4v & DVDFab decides that the file type is unsupported.
I have briefly looked at Toast which does accept separate video & audio files & allows setting that the files not be re-encoded. However while there are twenty odd menu templates they are all ghastly & there is no facility to customise at all.
So it looks like we are stuck with Encore.