When I make a drawing, I spend some time breaking leader lines to make the drawing more clear.
I always have to uncheck the 'Break Dimension Line' box, since it is always checked by default. I can't remember a time when I have wanted to break the dimension line, so I would prefer to have that box unchecked by default, with 'Break Extension Lines' checked by default.
I'm not sure this is exactly what you are looking for but within the Options>Document Properties>Dimensions there is a checkbox to "Break only around dimension arrows". Another option may be to set the break value to 0.