So, basically you're upset because when you complete the quest properly, you can't exploit the instant warp to the cloister anymore? The whole point of the NPC warping you there is so you can get there without running through high-level monsters...and let's keep in mind that this quest was meant for low-level summoners who need to fight their avatars, not lazy high-level ones that want to get to the cloister RIGHT @#$%ING NOW for whatever reason. Level 20 SMN gets their avatar, why would they NEED to go back there unless they intend to leech off of a group doing the full avatar or waking the beast?

This isn't punishment or irreversible damage. If you're that worried about warping to the cloister and exploiting that function of the quest, then just don't complete it ever. "Problem" solved.