Using the PPP model, we conducted an exploratory study on ST inversion in 3T triangular boron carbon nitrides. We began by validating the model on two prototypical 3T boron-centered triangulenes, 3T-a and 3T-b (cf. Fig. ). With realistic parameter values, we identified a significant portion of the parameter space for 3T-b (but not for 3T-a) that features a negative ST gap (cf. Figs. and).