The main idea why I turned my sight to N520 is Ryzen 1600's (@3600-3700MHz) temp of 76C in AIDA64 stress test and I had it in my arms.
Since several reviews shown that this CPU in overclocked mode maintained up to 66C, even with not a top cooler, it was a call to action to me.
Checked if a screws were tight, checked the fan's default grease - seemed ok.
So I wondered if a fan's facing is of any importance and this was the real case. PC case's fan was blowing the wind out of case and CPU's fan was blowing against. Considering the vicinity of these 2 fans, it is no wonder that they were bothering each other. After changing CPU's cooler/fan direction, stress test displayed 64-65C. Initially, it was a shock. Never thought that CPU fan placement matters.
As of now, I consider the temp to be ok, especially the fact that CPU is not loaded to 40-70% most of a time.
Further overclock might change the temp situation, though, and in that case, yeah, cooler upgrade might be required.
As of Gammaxx T200, I was told that it cools just fine and now I see that it does so (having installed it properly) for the money it asked.
The cooler you described is amazing and the temps you have just better than ok. Maybe one day I'll have to get one.