This has existed for Skyrim SE for a good long while, here https://github.com/KingKai-1906/Synth-NPCs-Face-Data
But what about Fallout 4?
We need facegen even more than Skryim, the default game comes with none & gens them as you enter each cell, in a large heavily modded load order this can cause a studder, who wants studders? Not me.
Lets try and repurpose this, first glance at the code makes it seem quite possible, so lets try.
If anyone else has already done so, please publish it so everyone can benefit, otherwise when I have time I will make an effort to do it here.
Cheers!