I was talking to a retired EC the other day and he showed me an interesting tool that he'd had made at a machine shop. It was designed to drill the hole through the soffet and roof for a service mast.
I didn't think to take a pic so will try and explain it as best I can.
It was made by pressing a brass bushing into each end of a piece of intermediate conduit. Next they ran a piece of rod that was longer than the conduit through the bushings. They then cut a drill bit extension in 1/2 and welded these onto opposite ends of the rod making one very long bit extension.
To use just mount the conduit to the wall where your conduit will be, attach a drill to one end and a hole saw to the other and drill straight through the soffet and roof. The holes are in perfect alignment.
This probably worked well on tract housing in the days when overhead services were popular.