Yes and no.
Yes, if you trade-in back to Apple reseller. Because they can detect your iPhone’s original capacity, if you really plan to sell it back to them, I can easily downgrade it back to original capacity, and they won’t notice anything at all.
No, if you sell it to a third-party. As long they’ve not authorized Apple shop. They don’t have a system like Apple to check the iPhone details. Sure they will take higher value than Apple if the iPhone has no problem.