This was a fix for lowered E9X. They have very little travel and if lowering springs were used, even less. Some coilovers would benefit from it also. I know mine did.
There could be drawbacks but I am not sure. The OEM suspension was designed to have a certain amount of travel with some of that into the bump stop. The bump stops are progressive so it the suspension reaches it bottoming out point more softly.
You would have to compare these to our OEM bump stops to see if travel would be increased.