Put DragonMounts on Curse?
I have asked Curse to consider putting DragonMounts up on their launcher. Currently we have a modpack titled Mythopoeia, that we have been playing on for about three years. Kids need a better way to access the pack, and our server, and the Twitch launcher would be the ideal way (plus my other modpacks are there). I hope we can make this happen! : ) Anna PS I know this is not the place for this ... but could not find anywhere else to comment. Sorry!
Have you tried to get into the Technic Launcher? it seems to be easier to get a pack into at the moment. We have a pack on there and have had no issues with it
I second this, but i think @Sunconure11 or @JonL98 should put his forks there - they are the only ones i know trying to bring DragonMounts to 1.12.x
Unfortunately, while I would do that, I have no clue how to fix what's going on with the dragon eggs. They are handled in a rather odd fashion. Everything else seems to work fine.

I found the dev's email, and I contacted him about it otherwise, though.
Could be something related to JSON block models? You could try your luck on Forge forums if it's that, or join MMD (a very nice mod team) on Discord and try to ask about clues for this issue: https://discord.gg/PhAcu8e
I'm in the MMD discord already.
As for the egg, it does use a JSON file for the model, but these eggs are the entities, created when you start hatching them. The egg and the dragon are technically the same entity.