When Should You Talk about Textual Criticism?

Thomas Hudgins, translator of the forthcoming book Aprenda a Leer el Griego del Nuevo Testamento by David Alan Black asks a question on his blog that I think might interest many of our authors and readers:
When Should A Bible Teacher Talk About Text-Critical Issues? Or Should He (or She)?
I’ve made some comments of my own at my Threads from Henry’s Web blog.