Robert, use of the en dash with spaces is what’s common in British English. I will follow CMOS (for US) or New Hart’s Rules (for UK) since that’s what the industry expects, and a proofreader who follows after my copyedits may assume I don’t know any better if I’m not following those standards.

For an indie author, though, as long as the style is consistent throughout, they can express a preference if they have a need to do things differently (as you’ve stated regarding your visual difficulty). It’s not my book; it’s theirs. But if they’re accepted by a publisher, their preference may have to bow to the publisher’s style guide.