Yes for whatever reason that line doesn't seem to do anything. Perhaps that was a feature that never made it in to the Galaxy Forge 3 but they forgot to take that out. Regardless its impossible, no matter what you put there the game will still pick the name at random from the list in the string file.

I am pretty sure I have seen this done with the text version of the map. I will take a look at, I think it was Celestial Bodies maps, and get back to you soon.

You can accomplish this with some basic modding skills. Each race entity calls on part of the string file for its names. So if you feel ambitious you can create multiple entities for each race (TEC1 TEC2 etc) and give each one its own list of names or a single name to pick from.

EDIT: Nope GF just allows to rename planets. Crud

So factions names, the specific ones for each race can't be changed, is that what your trying to do? I haven't the slightest idea to do this.

Asfaloth, Glorfindel's horse, now that is a name I haven't heard in a long time.