First of all I wanna send a big thank you to Valtteri Nietula. He created an UI which will allow you the rename the files in the class of xxxx folders I share with you here to the IDs of newgens in your save game. It's a little bit complex and you have to follow 12-20 steps to get it set up, but I tried it out myself and it works perfectly for over 90% of the players.
In the download there is also a readme file. Just open this one and follow his instructions step by step.
This UI gives a whole new dimension to the inclusion of newgens faces in your save games. The manual process for that is over.
Importan side note: The game language for the transfer of the IDs must be English.
Cheers to Valtteri!