Joseph: “Is it your contention that if someone’s Rov told him that it is not halachicly required to use CY, then his using only CY will not gain him any favor with Hashem or provide him any reward in olam haba?”
It is my contention that the Gemara says that when he gets to Shamayim HKBH will ask him why he did not enjoy the Haagen Daazs that HKBH specifically put in this world for him.