In any and all cases, set the idle mixture screws for the best possible idle quality in and out of gear. Lean settings will cause nozzle drip, and really "stinky" exhaust, which is more eye burning that a richer setting.
This often leads hobbyists to believe the mixtures are too rich. Lean mixtures are simply very difficult to burn, and when we don't put in enough fuel in PPM for complete combustion, a LOT of stinky fumes exit the tailpipes. A slighly richer mixture, in contrast will have a more complete burn, and a slightly "rich" smelling exhaust. A slightly richer mixtures also requires less spark lead, and works better with blocked heat crossovers, or none at all.
A common mistake made when tuning, is not allowing the engine to complete heat-soak before setting the mixture screws. The engine should be fully up to temp, and have been driven considerable before making final adjustments.
Ignition timing plays a BIG role for idle fuel requirements as well, just 1 or 2 degrees with some engine/cam combinations can make a tremendous difference in idle quality, in and out of gear, as each set-up has a "sweet spot" for the timing and fuel curves, expecially at idle speed.
Also keep in mind, that nearly an aftermarket camshaft is going to have different lobe positions, LSA, and duration than a factory camshaft. They most often reduce idle quality, just a by-product of their designs, as it takes more duration and more off seat valve timing to make more power in the upper rpm ranges. When doing so, idle quality and low speed power suffers, no way around it. With this in mind, fully expect to have to increase ignition timing beyond factory specs, and add some idle fuel, or both, for best results in all areas........Cliff