… I don't think that it's acceptable to watch the presentation of a heretic even for the purpose of learning about these evils.
As Our Lord Himself was not so exclusionary, none of us need be. Think of Matthew 10:16, for example. As sheep sent into the midst of wolves, the Lord tells us to be as wise as serpents. Clearly, there's only one source from which such wisdom can come. Think, too, of the parable of the Unjust Steward. Our Lord commends to us the plainly ironic positive reaction of the steward's master to his servant's dishonest actions, which were taken to assure him a post-dismissal welcome into his master's associates' households.
The point is that in this world of darkness, a world whose Prince is Satan (to use the repeated formula of John's Gospel), even the acquisition of knowledge that one may well require to get through the minefield of temptations in one piece and reach the safe haven of God's eternal presence can be fraught with peril. Yet as these hard lessons
must be learned, if they are learned from serpents and dishonest servants, so be it.
Put otherwise, you might not need to stick your hand in the fire to learn that it can burn you, but you do have to get close enough to feel the flames' heat.