When an engine has to provide consistent performance at all useable rpm bands with minimum instabiity the need for a different type of advance curve becomes evident. The most apparent for the average person is in heat generation. Of couse this presumes an individual documented run results with at least rudimentary instrumentation. Run a 35 degree advance at high rpm and note the temperature delta between that and a 26 or less degree advance at rpm above 7,000. Tuned pipes would also benefit from a different curve since pipes typically generate more heat when set up correctly. More rpm=more work=more heat. There are other considerations but I have to save those for work only discussions.