FPOBN:
Cant see many 4 engine or heavies making a steep slope like that, most of the time, we are trying to reduce the GPA to 2.8/2.5 to manage a descent queue...
The U.S. standard was 2.5 degrees, which worked great for Connies, DC-6s, and the like. But, it was too shallow for the jet transports. Thus all standard ILSes were converted to 3.0 degrees in the early 1970s, with 3.1 degrees being the max for Approach Category D.