Hi Adrien, thanks for purchasing the product!
If I correctly understood the situation, you need to use a larger value in the switch_radius_multiplier parameter. It’s explained in the 10th page of the documentation. If you’d like to use distance_based_deactivation as well, you’ll need an even larger value in the deactivation_distance_multiplier parameter.
I hope this helps.
CriErr, thank you! I’m busy with other stuff now but thanks for the suggestion 
macoll, thank you too! Are you talking about MODO’s MeshFusion? I’m learning MODO right now and that’s an awesome tool!