Is the vertebrate content of that study mentioned in the body rather than the abstract? Because it doesn't mention anything other than insects and plants in the brief. Instead it suggests insect+plant omnivory primarily.
"Based on our data and other studies, a diet consisting of several insect species, supplemented with leafy vegetables, rich in n3 FA's, would best resemble the expected natural diet of P. vitticeps."
For the sake of discussion.... I'm not suggesting dragons cannot eat vertebrates, or that they don't in the wild or that they should be part of the diet etc.... Clearly many will happily eat a range of non-insect prey. What is the judgment here for very bad idea vs what's ok to include in the diet? What benifit does "boiled lean chicken mince" have over raw chicken, or even over whole prey items like neonatal mice? What benifit does offering any vertebrate have that isn't provided with a varied insect+plant diet?