I'm going to give you my perspective since zen3 has the same issues, if not worse. First, these chips can run at 90C+ and not thermal throttle. Not saying that's the best idea, but the spurts of usage PBO causes should not cause an issue. The chip is designed to run hott when needed, but we all hate seeing those high temps. I have 2x 360 RADS with RGB push fans that just look cool, and 6 ultra kaze pull fans (push fans are not sealed and have plenty of gaps and ultra kaze's are sealed to the back). I use an EK Supremacy Evo right now, but have a Heatkiller 4 Pro in the mail to me after ordering it like nearly 25 days ago!
Anyway, in your PBO OC Menu in the bios, you may be able to set the EDC, TDC, PPT limits. Do a p95 run and watch what hwinfo picks up as the max, and then set each to that. It should alone be a 10C or so drop. Let me know how that goes because PBO is way better than All Core Fixed Voltage in Single Threaded applications and low usage scenario's by about 5-10% per my testing.
CTR is another option you could look into. 1usmus made that program. Stick with the live builds. If you need help using that program, let me know. It will basically test for max all core oc and you can set it to do a short run at a higher clock, and then default to a lower OC for extended all core usage. When low usage, it defaults to PBO. They also have a beta I've been testing that does it's own PBO, but I haven't had good luck with it yet. It's still Beta.