I stopped using T.D.C. a few years back for weathering. Spotty texture is good for what I do. If the spots are large, clean the nozzle. I just use it now only over decals. Seems they changed the formula and also raised the price. It has a satin shine since the change and is no longer flat.
Use Krylon clear flat as a substitute. I buy it by the box / case at Lowes. A large can goes a long way with a lower material cost as well.