as often as i open the trace path dialog, the Line style sub-menu is always collapsed (the menu where you can specify how much a line is dotted)

i use different kinds of lines, all the time - so the line style submenu should rest open or closed depending on the users input.
example.

#i open the line style submenu leave it open and apply a trace a path
#the next time i invoke the trace path dialog, i want to see the line style submenu already open, like the last time i confirmed this dialog