Originally Posted by subieworx
A bump stop such as the one used on AST's (short and quickly progressing to rigid) should be avoided and is as much an indication of appropriate travel. Even with 900# springs (stiffest available in 60mm from swift) in the rear and close to stock ride height there is only about 2.25" before engagement of the bump stop begins. This is very little when considering a loaded suspension that encounters a bump mid corner.
Can you explain what you mean by "cornering power" and how that translates into a bump stop adding mechanical grip and in what situations?
Just as you have indicated a bump stop that become very rigid quickly can cause a loss of grip in a mid turn with suspension already near or fully compressed.
Rubber, cellular polyurethane or just polyurethane, foam or what have you as long as it's progressive and provide a controlled bottoming you will have more cornering power than the sudden or short stop version, but only with the proper spring rates. I am sure you know that already.