Which version of HyperLynx are you using? I just ran a couple of simulation from BoardSim versions 9.4.2 and VX.2.3 using EZwave and the receiver thresholds are automatically shown with receiver thresholds.
Additionally, you can request waveforms in EZwave that are not available in the virtual oscilloscope viewer. From the Simulation Control dialog, click the Simulation Controls... button. Enable things like Test waveforms and Digital waveforms.
These waveforms are handy when debugging or documenting your simulations. The Test waveform automatically includes a cursor at the point where the voltage crosses the Vmeas level. The digital waveform at the receiver switches L - X - H when the pin voltage crosses receiver thresholds.
I hope that this answered your question and provided additional useful information.
I am running 9.4.2. It does not look like it happens when the simulation sweeps across different buffer parameters.
that's a good point. This brings back some fuzzy memory of a discussion about this feature when EZwave was integrated into HyperLynx SI. As I recall, the developers realized that sweeping model selectors might cause the receiver thresholds to be different at a pin. Since the swept waveforms are grouped, the group might have multiple thresholds associated with it. To avoid this confusion, they just left thresholds out of all sweep simulations.
One thing that might help is to add a horizontal cursor (menu Cursor > Add Horizontal Cursor F6). You can right-click on the cursor and move it to a specific level for a visual reference.