I use it to do the windows of a penthouse, but I do the windows traditionally as there is no way to get WFP gear up there.
It doesn’t get in the way, but then I’m not using WFP. It’s a ledge about 2 ft deep, quite exciting. It’s not a sheer drop, it’s a 45 angle, with some other balcony’s below, so not too scary 😁
Why would you need it on a flat roof? Is it quite narrow?