waspattck said:

I'm starting to gain an appreciation for how tough this BR menu authoring can be.......MultiAVCHD seems to shut off full-menu capability when it enters BR Mode.

IIRC, when importing the source, you can specify a trim to limit the amount of the file used. This means one can render a test version on a shorter part of the material so it doesn't take too long and you can revise the menus etc quickly. When happy, remove the trim so that the full input file is used.

ClownBD (Windows only) contains all the software needed to create a Bluray structure from an mkv, including TSmuxer.