So finally I broke down and got a new professional type airless high pressure pumped sprayer. It is a Ryobi, so at least I didn’t spend as much as I could have, but totally worth the money. To paint the ceiling, the brick, and all the stone a sprayer was a must, and the airless pump sprayer it is super quick and did not clog once. My only regret is I wasted two hours trying to get cheap one to work right.
There was no comparison at all to the cheap sprayers and it was super fast. It only took one pass to put the paint on for each coat, but be warned these sprayers really go through paint (because they are actually putting it in the wall!).
All done painting this corner of the basement! And now we have the right tool and technique for the other 3/4’s of the basement.