BartK You see, digital pianos usually have a much lighter pedal than grand pianos and the resistance is not realistic. By that I mean that in a grand piano when you press down the pedal all the dampers must be lifted up, which is quite heavy, but if you press down only a little, like 20 percent then the dampers are still partially resting on the strings and you don't feel the full weight of the pedal yet. On a digital piano the pedal has a more uniform springy feel.
This explanation really makes sense! Thanks @BartK
Although the Roland pedal I have is relatively stiff, it is indeed still is a spring with linear resistance. In Pianoteq I can customize the depression range where I want to damper to lift. But there is no way to solve its lack of a βbite-pointβ feel.