I've already spent a lot of time figuring out why it's not working,
I wanted to make it so even body and head accesories can be applied.
But what I've found the game may have hardcoded 3 animations only for Mannequins.
That means you can just make Mannequin have Salute, T Pose and Rest as now Vanilla Mannequins have.
Long story short, I can't make Custom Pose Animation for my mannequin coz all I can do is replace mesh model as I did and works now.

Why if you dont its not real nor is it going to be a good mod

No

Hey on the mod you made For bodys Can you make ir So we can Put hats on It and if we do I looks like it just feel on the ground in IN the ground Please do this if you have Thanks