I've just recently taken the plunge with blu ray authoring myself. I've found that encoding an elementary .264 file with 0 bframes and then not allowing multiavchd to do any transcoding is the best way to ensure compatibility. Maybe you've done this already, I just thought I'd put in my 2 cents. I looked at your project and didn't notice anything out of the ordinary but I'm a complete noob in this area lol.

If encoding at 1080p i guess I'd use something like this:

--crf 18 --preset veryslow --tune film --bluray-compat --vbv-maxrate 40000 --vbv-bufsize 30000 --level 4.1 --keyint 24 --open-gop --slices 4 --colorprim "bt709" --transfer "bt709" --colormatrix "bt709" --sar 1:1 --bframes 0

Also, there is an option in megui to import your chapter cuts and ensure that the first frame of each chapter is encoded as an I-frame which should ensure that each chapter is capable of playing correctly when jumped to.

Again, this is all stuff I've just read and I'm no expert on it :).