If it's not too dirty then try to avoid touching the very top frame when you wet. Obviously go close but just miss it by a few mm.
If you do need to get the top edge wet (because they are really dirty) then after you mop the window, while the window is still wet use a thick microfibre floor cloth over the end of you pole and wipe the top edge. Then blade off as normal.
If you are proficient using a pole then you won't have any runs after that.
A cranked angle adapter on the end of the pole, slightly offset, makes it easier to detail the corners with a cloth just folded a couple of times over the cone.
The fixi clamp is too much faff on just for detailing - (though it's OK for cleaning frames with a sponge the traditional way)