When hatching wyverns, they will have just enough food to survive until they are fully matured, no matter the server settings. Once a wyvern is tamed, it can be fed with just raw meat, which should be relatively easy to get if you are getting wyvern eggs.
This Is my guess/hypothesis if you leave a wyvern egg sitting on its nest for a long time and you get it after so long you have a big chance of getting triplets. Trust me I did it my first wyvern egg and I got triplets. Up so people know if they dont know they wont do it and get triplets