Ok so I was thinking about this in the shower lol. Like to really know what is safe you would have to have such a big group of chams to run your observations from and then later on passing a necropsy. They should all be the same gender male preferred to rule out female issues with eggs, they should all be from the same clutch so your dealing with the same genetics, same cage set ups along with temps, feeding and amounts, supplements. Everything should be the exact same for each one with the exception of the plants in the cage. Their entire life they should only have that one plant. With this being the only difference later on you would be able to know more detailed info upon necropsy as far as plants and their oxilates causing damage...
It would be a very interesting study. I really think this would be the only way to have a clearer idea. But you could take it further too. Two separate clutches with totally different DNA. I mean for this person that had the cham that died. Was it the plant or could there have been an issue of compromised organs from a genetic issue. After all we hear it all the time about Veileds being so inbred within the hobby.
I dunno I think I am rambling now lol