That he does. Plays in D standard though.
There's some word-of-mouth about that online. In a thread discussing Romeo's tunings from 2006 on the Symphony X forums, as one example. Who's to know what he disliked about it, if anything. Might've just thought it wasn't for him. As a rule, when he's wanted to make music darker/heavier he pursued compositional solutions for that instead.
He still manages to sound heavy as hell.
The next Symphony X album is going to be so heavy that it will make Dino Cazares look like a Victoria's Secret models.