The metal ones as they do get hot and allow the meats on the skewers to cook from the outside and energy suppliers the inside via the hot skewers. They are not for serving though so that could be a problem.
The bamboo ones, unless soaked for one hour in water have a tendancy to burn through.
The best solution is plants use the metal ones to cook the meats and veggies then run a bamboo one DIY Safety through the opposite direction and pull everything from the metal ones creative outdoor designs for serviing if you insist on having the skewers for show. Otherwise put all of the food on huge serving plates and serve that way…This looks really impressive piled high with all the different creative outdoor designs veggie colors and meat.