Is there a way to remove Messages / Inbox from the new sidebar menu?

I do not want to emphasize this feature on my site. We have a separate (Matrix) chat system, and really the same would apply if we were using Discourse Chat: too many inboxes is confusing. Since it’s used for flag and moderation messages, I can’t just disable the whole thing, but I’d like to de-emphasize it at least. (And it’s redundant with an entire section on the notifications menu anyway, isn’t it?)

If you just want to hide it whole, try the following css

.sidebar-section-wrapper.sidebar-section[data-section-name="messages"] {

That’ll do — thanks.