The Dior Dilemma

[Raynor]

His blood or genetic makeup doesn't change; he was just "granted the same grace" (Appendix A, ROTK).

Your quote is misleading. It reffers to the ability to pass over to the west, not to his immortality.

Elrond chose to be of Elven-kind, and became a master of wisdom. To him therefore was granted the same grace as to those of the High Elves that still lingered in Middle-earth: that when weary at last of the mortal lands they could take ship from the Grey Havens and pass into the Uttermost West; and this grace continued after the change of the world.

What is "a full elf"?
...
There is no reason to now call him an elf just because he shares their fate.

It wasn't just sharing their fate, but also their other abilities, which I mentioned previously. Anyway, do I understand correctly that you consider Men, Half-Elven and Elves to have the same "blood or genetic makeup"? If so, what would make a Half-Elven less of an elf, than a "naturally" born Elf?