It's a pleasant and innocent pastime to look at optical illusions, planning to be initially pulled to error but then to overcome. On the other hand, it's not innocent to invite certain kinds of emotional illusions, to pursue a line of thought that one plans to excite in oneself an unjust scorn for someone or a feeling of class superiority, even if one plans and reasonably expects to overcome these mistaken emotions afterwards. Similarly, it can be a valuable exercise to take what one knows to be a piece of pseudoscientific reasoning and put oneself in the shoes of the reasoner, try to feel the force of that reasoning from the inside, as long as one is confident that one won't be finally taken in. But to do this with faulty moral reasoning seems deeply problematic: it is a bad thing to read Mein Kampf or watch Birth of a Nation while putting oneself in the author's or director's shoes, trying to feel the force of the moral convictions from the inside, even if one is confident that in the end one won't be taken in.
Likewise, there need be nothing wrong with reading science fiction or fantasy that presents a world with laws of nature different from ours and to engage in the willing suspension of disbelief. It may even be fine when the world has a different mathematics from ours--to read, for instance, a story about a message encoded in π, a message that, we suppose, isn't there (at least not where the story says it is). But to engage in the willing suspension of disbelief when reading fiction that presents a morally different world--say a world where enslaving the weak is actually right (and not just seen as right)--is much more problematic.
Ever since I met it in Plato's Protagoras, I've been attracted to the idea that emotions are a kind of perception, akin to visual perception. But the above disanalogies need to be taken into account. I see two ways of doing this. The first is to say that emotion differs frmiom the senses qua perception. Perhaps, for instance, the senses present things as prima facie, something that needs to be weighed further by reason, while emotions present things as ultima facie. I doubt that that works, but maybe some approach along those lines works. The other is to say that the difference has to do with content. We might say, inspired by Robert Roberts, that emotions have as their subject matter evaluative matters of concern to one qua evaluate matters of concern to one. Maybe this makes the pursuit of emotional illusion problematic.
But is pursuit of all emotional illusion problematic? While it would be wrong to pursue a feeling of class superiority, would it be wrong to pursue a feeling of class inferiority, for instance to better feel compassion for people who have been socialized into such a feeling? I am inclined to think that even pursuit of a feeling of class inferiority is morally problematic. That's a feeling no one should have, and it is contrary to self-respect to feel it.