@d-healey I know that’s SWAM uses Physical Modelling
I have two Library's from SWAM (Clarinets and Saxes) which are Hybrids Physical Modelling and Samples, but this type of Portamento controlled over Velocity and Time is possible also with Samples and in Hise. Its a Midi manipulation.
Also is working in some Yamaha Arrangers like in PSR A-5000/Genos 2
with Samples, they are calling Crossfade Portamento there.

What is Crossfade Portamento?
Portamento is a musical technique that creates a smooth, continuous glide in pitch between two consecutive notes, instead of a sudden step. It's often used for expressive, fluid transitions, especially with synth or string sounds. 
The Crossfade Portamento on the PSR-A5000 enhances this by providing a silky smooth transition between the notes you play. It's particularly significant in the PSR-A5000 as it's designed to give a more natural and realistic behavior to many of its instrument voices, especially the Oriental/Middle Eastern ones like the Nay (flute) or Oud, simulating the expressive slides common on those instruments. 
️ Key Functionality and Control
The PSR-A5000's implementation of Crossfade Portamento includes new parameters for greater control:
• Velocity-related parameters: The feature is sensitive to the velocity (how hard you press) of the subsequent note. This allows the transition speed and character to be modified dynamically by your playing touch, adding a layer of expression and realism. 
• Time-related parameters: You can adjust and fine-tune the Portamento Time to control the overall speed of the pitch glide. 
• Interval sensitivity (Optional): Traditional Portamento can be affected by the musical interval between the notes. The PSR-A5000 often allows you to switch between a mode where the transition time varies with the interval and a Fixed Time mode where the transition time is the same regardless of the interval size, offering versatility. 
In essence, Crossfade Portamento works by smoothly fading the pitch of the first note into the pitch of the next, making the transitions between successive notes more expressive and fluid.