@User It might be true that they are being set to zero or it might happen setting zero value is considered as parameter not given inside the BSIM model. I am not an expert on it. I am trying to understand what has been provided to us from foundry in skywater-pdk. I think it is a good starting point to simulate a simple inverter to check delays with setting parameters 'AS or AD' according to the formula in the schematics and compare it with RC extracted simulation. Also, it might be worth the effort to understand the differences between the simulations with setting ad/as and without setting as/ad.