The title basically says it all.
It would be fabulous if we had a way to “harvest” xenocrystals from overgrown Ellydium ships. Either via an indicator that grows over time in the ship tree next to each ship, or the easier method: an away mission that let’s you send only Elysium ships, and rewards lots of xenocrystals instead of credits.
Maybe higher rank ships would get more crystals etc.