Im no expert by any means but to be honest, what you are explaining sounds like normal Ryzen behaviour. They work differently from intel cpu's and are constantly boosting to their max speed on 1-2 cores for brief periods on light threaded workloads. I had a 3600X and now a 5600X and they do exactly the same. The temp rises and voltage rises only last for split seconds. I get what you mean by this behaviour making the cpu cooler and other fans continuously ramping up and down which can be really loud and annoying but after buying a better cpu cooler it is no longer audible,(and my case fans are 2 big 200mm fans that are constantly on max rpm anyway,so im use to that noise.)
I running all 140mm fans, and the processor is liquid cooled. It get it might be how they act, but I still see no reason (by design) to go in and out boost mode for simple low-end stuff, you not gain and speed in open a new tab in a browser, and its certainly not needed. I would say a redesign of how boost mode works is needed.
All my PC's since 1996 have had a liquid cooled processor, even going way back to Athlon's, and I've never had a processor that could just all sudden rise 10 -20 degrees.
So when I game, which is a much harder work load on the processor, and the load is at a constant, my CPU runs at about 52 - 65C. So how opening a new tab for a web page can instantly create a temp of 50 - 62C does not make any sense. Desktop temp is around 37, so by going into boost mode to open a website, the processor is jumping 13 - 25 makes no since when it has water cooled copper plate sitting on it.
You can turn off Core Performance Boost in BIOS - CPU will not boost anymore - it will work 10-20% slower - but for games, you will still have more than enough power