Here are some additional herbs that i found overtime that may potentiate or at least enhance the experience. I don't mean to update old post but i believe Cacao has some true healing, entheogenic potential and should be brought back to light.
Mucuna pruriens - Natural L Dopa
Cayenne pepper - Used in All Cacao Ceremonies
He Shou Wu - Natural Bliss?
Ashwagandha - Amazing Adaptogen, Calming Nature
Maca Root Power - Great Synergy with Cacao
Chaga/Reishi Mushroom - Spiritual & Synergistic qualities
Spirulina - Extra PEA and Neurochemical Boosts
General Spices like Turmeric, Cinnamon, Ginger, Nutmeg, Cardamom, Vanilla ect..
Shilajit - Significantly enhances bio-availability of anything you take with it.
Sunflower Lecithin and Coconut Oil possibly? and or Cacao Butter(if using powder)
Mesquite, Lucuma and Hemp seeds(loaded with omegas, magnesium and nutrients) may synergise well with Cacao. CBD oil may also be awesome addition to a Cacao Elixir i presume. Bacopa/Gotu Kola/Ginkgo, Astragalus and Rhodiola may also potentiate. Others have already mentioned Raw Honey/Bee or Pine pollen. Saffron and Damiana as well.
If you want to take it to some extreme levels possibly Kava Kava or Cannabis Oil ect..
Though the river tells no lies, the dishonest standing on the shore, still hear them.