I think I have a copy-paste on this topic:
Loads will drag out the game, significantly devalue the element of surprise during the initial clash of opponents. That is, they will make the game less interesting. Plus, you will have to write a section in the rules with 100,500 cases of exceptions when a load cannot be taken. And also - with simultaneous turns, you roll back not only your turn but also the opponent's turn, which clearly changes the course of the game. Suppose the opponent has just had a difficult battle where every mistake was fatal - you take a load, he makes a mistake in the replay of the battle, and suffers because of it. Another argument against loads is that the set of spells changes. You can use a load to erase a good spell from the opponent. So, in my opinion, the proposal about loads in Heroes creates far more problems than it solves.