did i say "mm"? heh, i meant m (meters).
you know that theres a global scale in the render settings object? if you model in cm youll have to set it to 0.01.
edit: i checked it again, all scales are correctly exported, so if theres a problem, its most likely in your scene ^^
edit subdiv parameters:
max_num_subdivisions: 10
subdivide_pixel_threshold: 0
subdivide_curvature_threshold: 0.001
displacement_error_threshold: 0
subdivision_smoothing: false
view_dependent_subdivision: false
wrap_u: false
wrap_v: false