A quick refreshing on changing extensibility and stretch perception is here. In short, if we do not "lengthen" muscle, fascia, or nervous system as rapidly as mobility changes, we are changing perception of stretch. We normally expect these rapid changes to have just as transient improvement unless loaded or reinforced regularly.
The study summarized in this blog post on NOI Jam showed longer than expected improvements in hamstring mobility - 3 weeks after a single session of 3 sets, 5 reps, 5 second holds. Significantly less duration and time with longer improvements.
Why? The thought is that the stronger perception from the added neurodynamic component may have changed the perception of stretch more effectively than other forms of stretching, leading to the lasting improvements. Improvements were seen on both the ipsilateral stretched LE and the contralateral LE.
It's great to have your biases challenged and with mine going the way of lighter and lighter year after year, sometimes it's good to have the pendulum swing the other way and have some "stronger" options if the light ones you normally use are not demonstrating the expected rapid changes.