The custom loot tables in this mod or loot injections, whatever they do to get eggs in chests have broken a few loot tables. Simple dungeons and mineshaft chests are showing empty chests for me on a pack I put together with a good amount of mods. I'd love it if I could turn them off from any early-game chests, its far more rewarding to only earn them by slaying the dragon and finding eggs in end-city loot.
Even allowing us to disable chest spawning entirely would be a nice feature for servers and many players in general.

end city chests are empty too
Dragonmounts 1.0.3

I have this problem when I have Rings of Ascension along this mod. I posted an issue on their github.

i do have Rings of Ascension installed too. i will look at the loot tables for it.
i have been using Dragonmounts 1.0.2 for the moment, the .json loot table injections are working in that version. haven't had time to check end city chests, though if they are still broken it will be Rings of Ascension as Dragonmounts 1.0.2 has no .json for end citys

Dragon Mounts no longer uses jsons for the egg loot tables, as its not compatible with mods that also modify those tables. Please use the latest version, as that patch has fixed this issue.

focamacho/RingsOfAscension#2 (comment)