On pitched roof extentions if you can't wfp it from the ground or using a ladder to the roofline & then use a wfp then in my book it should be left out.
I've found an ankalad stabaliser (outriggers) fitted to the ladder & microlite standoff resting on roof tiles gives you a very stable platform to work from to be able to use a wfp on hard to reach glass etc without the need to go clambering over pitched roofs.