Constraints on b_ϕf_NL as a function of b₁. Blue and orange symbols show results for the Gaussian and the non-Gaussian simulations, respectively, assuming that the P(k) variance is computed from the FASTPM mocks (see Sect. 4.2). By subtracting both, we obtain the green points. Thanks to the so-called matching technique, these points have smaller uncertainties (see Eqs. (16) and (17) in Sect. 4.3). Grey lines indicate the expected value by assuming the universality relation, with the dotted line for f_NL = 0 and the dashed line for f_NL = 100. In solid circles, we use the best fit to Eq. (15) for estimating the power spectrum variance; in rings, we use the extrapolation method. Here, mass bins 0–9 are shown.