[phenixbb] difference in B factor for NCS groups

Dear all, I'm working with a structure were one NCS copy has significantly high B-factors than the other. That one copy makes few crystal contacts to stabilize it. Is there a recommended way to adjust the refinement to reflect this ... using TLS? Decreasing b_factor_weight? Is there a way refine a group_b to be added to the b-factor of each atom in that chain? --James