Ok so I have removed the eyebrows keys but also the eyelids position keys that were the cause of the glitching shading issue. I have included the new animation with the changes you made previously so it's all merged there.
On top of that, while I was testing this out with Tanis model I noticed that his eyes weren't moving, and I realised that his eyes nodes were called eyeR and eyeL instead of eyeRA and eyeLA which is what the game expects because they are called like that in the supermodels and the rest of the models. So I have renamed them and now it looks so much better. There are actually two files of the same model head (I don't know why, the only things that changes it's the texture but whatever) and both of them had the eye nodes wrong. So I included them as well here in case anyone else wants the fix. I don't know if there are any more models with the wrong names, I haven't checked them all. The one Tanis uses is N_TatComA_M, I discovered the other one because I previously thought that was the one for Tanis but it's just the regular asian head.
Btw I was testing this with the vanilla Tanis model but I see in your video that you have him modded, so I don't know if this is gonna work but it should.
various fixes.rar