I stand at each end extend the pole and do them from the side when I’ve done as much as I can do from one end I’ll finish off from the other end,most roofs are not designed like that these days they leave room although you still get bad builders that don’t allow for the cleaning of glass like this.
The best ones these days are the ones on a Zinc roof with glass with no seams at all just welded glass,no cheap plastic to clean.