Loading Effect of Digital circuits on Analog Circuits in AMS Sims

I'm trying to perform an ams simulation to capture accurate timing for the signals crossing from analog to digital and vice versa I've added the sdf command file and indeed have seen the delays in the signals.
But I'm wondering if the simulation is correct, the input signals of the digital part is going to a buffer, this buffer has a certain capacitance that will affect the delay of the analog circuit driving it. If I understand correctly sdf files include only delay information not loading information. Same goes to the output signals of the digital part, the strength of the output buffer will affect the delay the analog circuit after it.
So how do I capture this missing part in the simulation