Could you provide a few concrete examples of trigger warning usage that has had an “undue burden on freedom of inquiry”? Because the examples I’ve seen don’t seem to have that effect, and in fact seem to be pretty good pedagogy.

A few real-world examples of “intellectual safe spaces” would be helpful too — it seems to be an even looser term than “trigger warning.” It’s easy to fall into the realm of “unfair caricature,” which you so rightly oppose, when discussion is kept in the abstract.