As always a DM can do whatever they want, but loose interpretations of these rules to restrict bargains that are unfair to outsiders go against many of the example usages of these spells. People argue that "unreasonable commands" is not defined, but it is defined; via usage. You don't get to ignore examples because the rules were unclear, they actually become far more important in such situations.
The logic would be bad faith, since you're telling a player that something that is clearly possible within the rules isn't possible within the rules.How is it bad faith? Bad faith is doing something specifically to try to break the game in the first place.
Huh? I literally said in my first post that it's necessary to restrict this if you want the game to function at all. I can disagree with poor argumentation without disagreeing with the conclusion. I encourage DMs to restrict players from breaking their game; just be honest about it.The only reason you think it's bad faith is because you don't want your freedoms infringed. It's ok, you don't need to play with big bad restrictions.