Full World Cross sync with realms subscription

Hello Mojang I think that there should be a fully automated cross device world sync included with the realms subscription service. I think it should have an on off switch in the settings and then one in each individual world to turn on/off. I think in here there should also be a toggle that makes it so any add ons [mods] in a world that was cross synced to your device is automatically downloaded to all devices. Sincerely -A8pizza