I've seen it done on WSM's. I think you'd be hard pressed to get the grate high enough over the wood on a kettle. Maybe you do away with the charcoal grate or something, but I'd worry about hurting the kettle.
I put some 1/4x20 studs through the upper part of my rotisserie ring which “might” get it high enough but, I have my doubts. Why not just go indirect and finish with the splits?