Should be doable to add that. The BLDC needs to add a proportional (or any other function) force against the rotation direction until it reaches 0.
Sounds reasonable, wonder how that would actually feel in real life? As far as I understand, this would pass through digital parts, adding a little bit of (maybe noticeable) latency, but I wonder if the latency gets high enough for it to be a bit jarring that the resistance is dynamically changing as you apply torque.
In practice, when latency is small enough (on the ~1ms level, which is trivial to achieve using even pretty cheap parts) it's imperceptible.
I sometimes develop control loops for prototype systems which use a motor to emulate a combination of spring + friction damper, and even though I know that my code only runs every 1ms, it's really remarkable how much it feels like a real continuous analogue system.
Another good example is power steering, which uses a motor to remove resistance instead of add it. If I understand it correctly, it senses you applying torque to the steering column and adds proportional amounts of boost - but because it happens so fast, it just feels like the steering is magically lighter.
This is all fairly normal in robotics, under a subset of (slightly overloaded naming sorry) “impedance control”