I'll try the .Scale function. I changed the actor file:
ACTOR3DX
{
NAME = "trinity"
CAPTION = "Trinity"
INTERACTIVE = TRUE
ACTIVE = TRUE
SCRIPT = "actors\trinity\trinity.script"
SHADOW_IMAGE = "actors\trinity\shadow.png"
SHADOW_SIZE = 12.0
LIGHT_POSITION { -40, 200, -40 }
SHADOW_TYPE = "stencil"
; SHADOW_COLOR { 0, 0, 0, 128 }
; SHADOW_MODEL = "actors\trinity\trinity_low.x"
SCALE = 500
The scale used to be 180, but in the game, she's still the same size. The size changes in the preview window, but not in the game.