Just so you know, both the “normal player size” photo and the “riding player size” photo are exactly the same image.
Besides that, I’m not exactly sure if this would effect the character in the same way, if you actually put a saddle on it instead of riding it without one via force tame. Did you try testing it with an actual saddle to see if it still resizes your pawn?
And also how exactly are you resizing the Rex(s)? I have a feeling the method you are using is causing this
- Sinari