I don’t really see the need to convert your 24-bit montage to a 16-bit montage. I think most people keep their montage at 24-bit but just make the end file result as 16-bit with a dither plugin inserted.
If you need to make a DDP image, audio CD, or render WAV/AIFF/mp3 files that are 16-bit, you can simply render them to your hard disk from the 24-bit montage and do what you need with them. Just be sure there is a dither plugin as your last insert that is dithering to 16-bit. If you want a single file of the entire CD at 16-bit, you can render the whole 24-bit montage as one file (with dither plugin as last insert), but to add it back to a new montage to make your DDP, CD or render files is an extra step that isn’t needed in my opinion.
I think what PG is saying (and I agree), it seems like an extra step to make a 16-bit montage from your 24-bit montage, and then export the files that you need.
In the 16-bit montage that you pictured, there is just one clip (or so it seems). One clip can’t contain metadata for all the songs as it’s just one file.
Maybe I’m missing something but I think that making a 16-bit montage is an unnecessary step unless you are trying to do something special that I’m not understanding.
If you want your rendered files to have metadata embedded, you may have to look at the special metadata section that is new in Wavelab 8.
I have mine setup so that whenever I render a WAV/mp3 etc. from the 24-bit montage, it automatically embeds any metadata that is allowed in the file format, such as artist, song name, album name, track number/track total, ISRC, artwork etc.
It’s really nice once you make a preset for the info you normally use.