People in my circles often think of Brad Warner as a Buddhist radical. Actually beyond his being a bit in your face, and willing to talk about sex and rock and roll (and the occasional monster movie), he’s a remarkably conservative advocate of the “shikantaza only” Soto reform movement established by Kodo Sawaki Roshi.
You want radical, attempting to go to the root no matter the cost, check out Stephen Batchelor.
And happy birthday, Stephen. And fond wishes for many more to come…