Sorry, what?

I think he is referring to the movement panels. The 4 wire H-Bridge has two PWM sliders for the individual speed control for each motor connected. The custom Movement Panel only has the one slider for speed (unless you have changed this in a recent release - I can't say I've looked at the custom Movement Panel for months). I guess he is asking if the custom Movement Panel can be updated to include two sliders for two different variables which can be used in the custom scripts to control the speed of each motor independently? (@Techno, is that what you meant?)

@Techno, if that's what you are after there is a control called Script Slider which you could add to the project and use the variable set in the script slider to set the speed within your custom movement panel.

If that's the case, then no - there wouldn't be a point to do that. The point to the custom Movement Panel is for people to create their own commands for the movement method. In which case, you would also be responsible for the speed of each wheel for smooth cornering - like the PWM HBridge.