Whilst playing with some larger datasets on MDL-25544, I noticed that things were a lot slower than I would expect, so I did some profiling.

The profiling pulled up some easy-to-address things which can knock off a sub off the page load. These are things like:

• unnecessary use of html_writer in a loop;
• repeat calls to fetch gradebook user preferences without caching
• repeated calls to get_string for the same static string