When you cast reiterate it seems that something is not working correctly. Because I have just finished a match where reiterate continued to cast a copy of itself again and again.
I think the problem is that the clause about not copying reiterate is not implemented (correctly) but it is possible that there is also another problem.
Because I tried casting reiterate twice (same result) but the first time the spell supposed to be copied was not the last reiterate in my hand (I had another one in hand) the second time I know for sure the last spell, was Heat shimmer.
Therefore I wonder if It is possible that reiterate targets the last spell in the graveyard - not in hand as written.
BTW I played the first node of Tour de Ravnica. The event support was Cipher (copies a non-copy spell when cast) this may have an influence on reiterate. But I still think reiterate can target another instance of itself.