I just finished the show and became a favorite among others. I think making it as a half satire was original and good decision. I laughed my ass off watching the unhinged Ethan Hawke as John Brown rule the screen.
But, at the same time, as you pointed out, there is an important story and message here that too few people know, unfortunately. John Brown wasn't insane, although sometimes he appeared to be, but he was more conscious and intelligent than some pretentious and wannabe people.
Also, the timing was excellent, too. I hope that it will reach a wider audience because it absolutely deserves it.