I have no qualms with anything you posted, and generally agree. Up until April 1 of this year, thre has been a historical pattern, but there was no requirement for a bound delegate to vote for the same person at the Convention. The new rules seem to state something like that in the link you provided, but I can't find that wording anywhere else. And it isn't reflected in other R writings or sources. In the past, a delegate who chose to change their vote would be effectively ostracized from the RNC. They'd lose party funding, party support, etc. It would effectively end their career as a Republican, in most cases. But that was pressure being applied through financial means. Not a rule that they cannot break. One of the two factors that play into how Republicans choose delegates, is "Party Loyalty." With the entire GOP machine slowly turning against Trump, that might mean that at the RNC a "loyal" vote might be a vote against Trump. No matter how this plays out, the tiger is eating its tail. And the GOP will not survive this. What will fill that vacuum?