I think this has to do with it.Im also a big dude.im 6foot 3 and weigh 110kg
I used to get a few hours out of kool chains,snapped 3 times in one day. Ive tried every sort of strong chain.
I was sick of breaking chains so i got the khe collapse chain(prone to stiff links) used them for ages,probly 1.5 years. Never snapped one,just replaced when got to many stiff links.
when i build up my new bike,becuause i was making it lighter i opted for a lighter chain,now rocking a kmc 510hx and its going strong. been using the same one since august with no issues,also using on on my brakeless bike.
I found that i was consentrating on my feet work alot more and not being as brutal it became second nature and my riding has gotten better im not really killing chains like i used to.
FWIW i still use the joining clip(due to sucking at joining chains.) ive never had any issue with the join.ive always snapped my chains away from the joint.