There is no objective answer. They're rhetorical questions. If you're trying to answer the questions and present an argument to me instead of reflecting on why I asked those questions, you've failed to understand why they were asked.
The idea is to get people to explore what is and isn't cheating. Some people here seem very adamant that changing max hp during an encounter isn't "fair." If that's the case in their world, then I'd like to understand where fairness ends and cheating begins. I think if someone feels as strongly about it as this thread length implies that that should not be a difficult task.
So, I ask again: Is it fair to set an NPC's hp to maximum hp? Is it fair to do that *after* initiative? Is that *really* that different? Is it fair to set an NPC's hp to higher than maximum hp? Is it fair to do that *before* initiative? So, is it fair to set *all* NPCs to maximum hp?
600+ replies in and nobody has come up with a good answer. It's time to explore different models because the example presented by OP is not adequate any longer.
Look, the point of a discussion is not to win. This isn't a trial. There ain't no judge. There ain't no jury. This isn't high school debate. There ain't nobody polling the audience. Ain't nobody going to give you a root beer and pizza party. The point of a discussion is to understand what the other person is thinking. To give yourself another perspective to consider. If you go into a discussion with the goal of legitimately changing someone's mind even when they disagree with you, you're not going to do it. You can keep arguing and make sure that you get the last word. That's all you'll get, though. But ain't nobody going to hear it. Worse, by going in with the mindset that you're going to win or change someone else's mind, you're not keeping an open mind yourself. If you're not open to what other people say, and don't honestly consider their opinions, why should they continue to do the same? And if they're not listening to you... well, what's even the point?