Sturdy Elytras

The Sturdyness enchantment comes in levels up to V and can be applied to elytra in play. Its effect stacks multiplicatively with vanilla Unbreaking III, and the game checks Unbreaking first, then Sturdyness. With Sturdyness V and Unbreaking III, an elytra lasts about 23 times as long as a standard elytra. Each level costs more experience, with level III at 8 times the cost and level V at 32 times the cost, and the Mending efficiency falls to 3% at the highest level, so a maximum-level elytra rarely breaks and repairing it becomes a significant investment.

The mod is server required and client optional. It needs to run on the server, and players can add it on their side, but a player who only joins a server does not need it. A datapack-driven enchantment API mod is enough to work with this mod, and it can run on a server alone. The enchantment is not accessible or visible on a client that lacks the mod, so the server side is where it has to be installed. Files are published for Fabric and Quilt for 1.19.4 – 1.21.10, and the code is open source under the GNU Lesser General Public License v3.0 only.