I've done quite a few asbestos shingled roofs. These are purpose made for roofs,...not just someone deciding to use them on the roof instead of for siding the house. Although, probably are basically the same thing.
Not trying to be a critical,...but why aren't you spraying that roof from a ladder at the roofs edge? Man, all it takes is one slip and your whole life will most likely be changed,...possibly even dead. Honestly ,...that is so dangerous from my vantage point. No money is worth falling,....we've all done it,....but looking back it's like I can't even believe I was that careless. Ok,...maybe it was a little critical,ha,ha...not just pointed at you though.