michaeldc said:

FYI Mac users: to extract the files you want in order to make a blu-ray disc from an MKV was something I hadn't done before but a little research and I found MKVtools which can extract what you need before remuxing using tsMuxer to create a blu-ray compatible folder.

I had previously only used MKVtoolnix for remuxing MKVs but had never considered creating a BD from the files contained within. I had read that people can use MKVtoolnix to demux and then also create a BD compatible folder but I think you need certain compatible GUIs that only appear to be available for Windows as neither of these options appear in the Mac version.

You learn something new every day!

Thanks for the info. Was just about to research this.