I haven't used dowels in my cham cages for several reasons...
They look boring. I like natural barked branches instead.
Naturally shaped branches may be easier for your cham to climb and the variable shapes and diameters will exercise their feet more than uniform dowels.
Dowels are made from soft woods, and unless you seal them well they will absorb moisture and mold. Also, they might be harder to keep clean. Some chams rub their vents on perches after pooping. It might be a type of territorial marking but I'm not sure about that given their poor sense of smell. If you have to keep scrubbing them the coating and paint may wear off exposing the soft wood to water again.