Following a discussion in the general forum here is an official wish:
that the fillet/join/trim tools will be modified to erase the portion of line opposite of the intersection to the portion that is clicked. Perhaps it is worded better by ybalx:
"Back to point on the command, and perhaps this belongs in the wish list forum, but a solution to this problem that would speed up the routine would be to force the break/trim/join routine to cleave off the section opposite the intersection of your selection as a default. Therefore, if you select two lines on the sections that you want to keep, the command action would effect the opposite portions..."
thanks,
macitect