We analyze the appearance of the trilinear squark-Higgs couplings x_q in Green functions in the Higgs sector of the MSSM and in threshold corrections to the SM. The results are constraints on maximal powers of x_q in QCD-related loop corrections. In practice these often imply all-order resummations of leading or subleading x_q contributions in SM-parametrized expressions. We present a variety of all-order resummation relations for ∆λ which include such x_q-enhanced terms and different orders in Yukawa and gauge couplings. We contrast which terms cannot be resummed.