I found a reason to re-enable SMT on my 2700X, fired up 16 threads at 100% and started to find the thermal limits the Wraith Prism -- and the tolerance threshold of my ears!
So, I ordered a Be Quiet Dark Rock 4. I got it installed today and temps dropped by about 6C. I was a little disappointed by the temp drop, but the noise drop was awesome. It's so quiet that I set my fan curves to be much more aggressive -- and traded some of the quiet for a little extra cooling.
It connects to the stock backplate and is dead easy to install on AM4, as tower coolers go. Joker runs through it here:
https://www.youtube.com/watch?v=R5_sRqpk1wA&t=318s . It comes with only one fan though and the brackets won't work with any of my spare 120mm's -- and other brackets won't work either -- so I haven't bothered to do a push-pull test yet.
Edit: I've added a second fan. Be Quiet sells their fans for too much ($25 on newegg for 120mm!) so I used a Fractal Design fan that I already had. However, the BQ fans are a bit non-standard -- their mounting holes are on a centered, thin dogear, not a full fan-width dogear like most. I had to rebend the BQ mounting wire brackets to work, but it's snug and tight and dropped my temps by about 3c. I turned my fan speeds back down so it's *reasonably* quiet again at 100% load.