The voices not working (with meta file) are Premium voices.
You need to add a 4th file (data???.dct) to activate the voice.

But there is a big problem: How to generate this .dct file ?
I don't know how and if it's possible.
I don't know if it's generated in the same way as the Tomtom Android 1.4 version. If finally it was the same way, you need the Meta code for the Premium voice + an activator program + the "Device ID" of your Tomtom Go Mobile App. The 2 first are easy to find but I don't know how to find the third.

Actually, I only use Tomtom voices without .dct files (therefore no Premium voices).