First off, I like the black tape around the stabilizer end cap,....looks just like mine.
But anyhow, that is a steep roof and the product wants to run off as soon as it hits,...already discussed. I've done a few of these and the lichen on them seems to get so hard a resilient for some reason. Add some hydroxide to your mix, that should give it the extra punch it needs to get it off,...the lichen and moss will turn more black than bleached out though. I usually kill it with hydroxide mix and then bleach it back out with regular SH for visual effect.
As you probably know, hydroxide is hot, so be careful what surroundings you get it on. probably 1 cup per 5 gallons will be hot enough.
Just be careful though!!
Jeff