The MC chapter on smoking talks about the importance of surface moisture. When they smoke after SV cooking, they do an intermediate stage in a warm oven to get rid of excess moisture. You want the surface to be slightly damp / tacky. More moist than that, the smoke will likely get trapped by surface liquid that drips off. Drier than that, too little smoke will be adsorbed onto the surfaces. I gather that the SV / warm oven / smoke is their favorite method.