Tank torsion spring suspension

[Vipera]

I had already created couple of tank rigs using Craft Animation plugin following the tutorial in documentation. There are two things I wish were improved in plugin regarding tank rig though. First, current simulation is done based on 4 wheel vehicle rig. What is fine if tank is moving above about flat surface. But for the rough surface like a small but tall hill at its highest point such rig doesn't work. The front wheels will be on one side of the hill while rear wheels will be on opposite side of hill, making top of the hill penetrating hull between front and rear wheels. I would like to have ability of extra wheels to work as suspension rather then just idle wheels. Second, the suspension of the tank wheels do not work correct. Most of the tanks have torsion spring suspension rather than shock absorber or damper. With the ExtraWheel I can simulate only damper which goes up and down but torsion suspension works in a different way. Could we have some improvements for tank rig suspension, please?