I have found at least 3 tracks of online encounters where I was chased by enemy fighter(s) in the clouds. Human pilots, not AI.
https://www.mediafire.com/?nhz92xu9svj3edy
(please note readme file)
When I watch these track records I see that in majority of cases the enemy fighter does not follow my aircraft in the cloud. He either climbs or go around, sometimes below. And when he does follow me, he does not shoot. Yet Bf-110 gunner can spot the enemy in any visibility - guter soldat, ja!
Sometimes, as it's seen in SBD vs Bf109 encounter the enemy fighter does not open fire when both of us are in clear blue skies.
My initial conclusions:
1. Clouds sync online DOES exist in some form.
2. Sync is not perfect, probably. "My" clouds and "his" clouds do not match meter to meter. I assume there is some margin error.
Three tracks do not make the representative sample, of course. But at least I know that my "hide and seek" tactic was not pointless
In my opinion, Sniperton's Theory is credible.