I'll point Kevin to this thread. He can read it all and comment if he wants to.
Kevin's still very actively climbing - and very hard. He's at Nuna most Tuesdays.
From conversations, his earlier creations were more the result of hand drilling, rather than a desire to be outrageously bold. There was nearly always gear/bolt at the crux and then it depended on how hard the rest was!
He has added a bolt to some of his older routes - except when he gets distracted by another new route next to the intended retro as happened at Buffalo with me a few years ago.
Michael