
HI Steven. Thanks for your ongoing interest in metal. If it's possible to make about a 1/2" saw cut into the stucco, it's great to do that parallel to the roof deck and then insert the flashing into the saw cut reglet and seal it.
If not, the flashing can be brought up the wall, held in place by a terminator bar if necessary, and then a trough is made at the top of the flashing to hold sealant against the wall.
Have stucco house with stucco sided dormers.
How is best way to handle sides and front of dormers with shingle style of metal roof?