Congratulations! You've found the culprit!
I wouldn't sweat the engine compartment temperature all that much. Contrary to what I've read, mine gets up into that range, too, and your CHT's are running quite cool so they're getting lots of air.
On a 90º day and blasting down the highway at 70mph or so, my setup (2,110, bigger cooling tower, later fan shroud, bigger fan) runs at 204º - 207º and I'm very happy with that. If I get off onto secondary roads it drops to 200º. If I climb a long, steep-ish hill it creeps up to 208º-ish but has never hit 210º. I'm fine with that, too.
Sounds like, with the fan switch change, you're in the right ballpark, too. Make that fully automatic and reliable and rave on!