Are there any exceptions that allow an  electric smoker which uses a small amount of wood for flavoring but not cooking to share an exhaust hood with other gas and electric cooking equipment

NFPA 96 section 14.3.4 has a specific exception for gas operated equipment, but there is not and equivalent section for electric equipment. This piece of equipment uses a small amount of wood where the intent is not to ignite the wood but have it smolder.