I swear the only place I've ever heard about this "Spong" guy is from #triggered religious conservatives on this forum. After quasi-associating with the Episcopals for over 5 years in real life, I've never once heard a thing about him - I doubt many rank-and-file Episcopals have idea who he is.
Spong is a good strawman for conservative Christians despite having been retired for well over a decade now. Most Episcopalians don't deny the divinity of Christ and Spong never had anywhere near the kind of influence that the Albert Mohlers and Franklin Grahams of Christianity do.