Such a nice looking fan, I remembered your two old videos of this fan running (at your old house), back at the time when RU-vid looked a lot different than it is now (which was also at the time I watched your first Garage Industrials video as well).
Yes, the cap is removable and any light kit with a threaded stem or two mounting screws can be added. Translation: Practically any light kit will work with this fan.
Except that these are NOT outdoor rated. I don't know where that common misconception came from, but they are indoor only. When it comes down to the little details, the two models are also very different.