I was messing with animation blueprints and made the crouch animation. I realized that I still had problems with some animations that can't adapt 100% well over the Metahuman so I toke a break to think what to do. I was playing to Return to Monkey Island last weeks meanwhile. What a great game! Thanks Ron Gilbert!
To speed up the making of my game prototype, finally, I decided to use a realtime retargeter over my Metahuman in the aniumation blueprint using a Unreal 5 mannequin base. Then I get the library animations and transform them into Unreal 5 Mannquin animations using a retargeter from Unreal 4 Mannequin. The result it's far to be perfect but it will work for now.
This is the result with the crouch animation:
The problems that I refer are things like weird moves as you can saw on Mark's arms or "levitation" of feets with some animations:
In a future I will need to record animations directly over the Metahuman to get better results.
My next step is to make an enemy that can look for Mark an try to catch him.