I too like to use sharp burrs whenever possible, but don’t go resharpening
or disposing of those dull ones! I find that if I’m trying to clean up or
polish a hard to reach area a dull round burr or one with a rounded tip
can do a great job. The action is not so much cutting as burnishing,
which is what is needed in some of those hard to reach areas. When you
later try to polish that area later, you done loose the detail trying to
get it nice and smooth and shiny.