Not sure about Doug’s or TTI if you can get a long filter on there without the adapter.
I don’t get the hate for the adapter. They seal FAR better, they allow a long filter. In fact I used to use a Baldwin filter that was longer by I think an inch or a bit more and had less than a 2 psi pressure drop across it at 7,000 rpm. I don’t think that Baldwin filter will fit any header without the right angle adapter.