Don't know because I haven't looked at the code, but it appears that there are certain things that when they are called to output/print, AC is using a CR 'plug-in' to prepare/format/structure the output.
Not surprisingly, that eats time, CPU, and [sometimes] execution.
Whatever changes are made would be fundamental, but I suspect that some folks would choose plain text output, even if it looked like notepad, over elaborate formatted output.
Probably has something to do with starting out with mainframe output onto yellow teletype paper and my training, but I have never had affection for "Pretty".