I haven't tried it recently, but I probably will. In the meantime, maybe this will be useful, although it is not really clear to me: https://github.com/Kitrinx/Atari7800_MiSTer
What is a PDL adapter?
Edit: I just tried it and it is still working for me. I am using the core from 12/27/2022. I calibrated my D9 by pressing both paddle buttons when plugging in the D9. I went in the core menu and changed the first port to Paddle. I launched Kaboom and pressed the button on the paddle and it recognized it and it worked.
Edit 2: I just ran update all, and I saw that it did something with the palettes in the 7800 core or something. My paddles are no longer working. I will continue to test.
Edit 3: I got it working again. I don't know if it made the difference, but I replaced the input_04d8_f6eb_v3.map file on my MiSTer with the one from the ZIP file in this post: viewtopic.php?p=66551#p66551 Then when I tried Kaboom, I think I grabbed the wrong paddle first. What ended up happening was I could use the button from the other paddle to start the bombs dropping, but the steering was on the paddle I was holding. Then I loaded a different core and loaded the 7800 core again. This time I moved the other paddle first, and the button was on the correct paddle this time. I always use Kaboom when testing because you can hit select and do 2 player games and you can see things easily without the game going crazy.