For complete triceps development you’ll want to re-position your arms for greater long-head stimulation.
Students of anatomy and kinesiology might have an advantage over the rest of us when it comes to triceps training. Not only do they they know the names of all three heads (lateral, long, and medial), but they also know how each head moves. That means they can figure out the best ways to target each one. But you don’t have to take an anatomy class to know what they know.