If Trump has a majority of the delegates, he shouldn't worry about what the Convention does. If Trump doesn't have a majority, he may find that not everyone is prepared to roll over for him.
It won’t matter if he has more than 1237 delegate if they write a new “rule” that only candidates who have previously held national elective office are eligible.
They are sovereign, you say, and can do whatever they want, so they could write that rules, correct ?