Do you have a source for C.S. Lewis taking on the name 'Jacksie' because of a childhood pet? I only saw that suggested in a book by Douglas Gresham, which is a very late source. Warnie had no mention of a pet in his much earlier treatment.

As for whether it's "quixotic" to ask for "pure" platonic non-sexuality between men, I'd ask if you're sure it's not sexual between men in Plato's circle, or between Don Quioxte and Sancho. Before you try to rip sexual feeling from the minds of men you've never met, perhaps you might find a more apt metaphoric base.