Actually, I spent several days investigating the HAARP facility a few years back during Dane Wiggingon’s scare campaign about it. And as an RF and antenna engineer, it didn’t sum up to the hype, IMO. Last time I looked it was a facility that had lost its government project support funding and was advertising itself out as a TEST BED for RF experiments involving RF atmospheric investigations to other agencies and contractors.
And, IMO Mt Pinatubo had nothing to do with HAARP or any of the other “20 such devices” worldwide you mentioned - it was an internal geological volcanic event unconnected with any possible atmospheric RF event such as HAARP.
So is 5g dangerous. I expect the dangers are over rated but I know little in this area.