I know one can use {code} when desired, but I am far more often needing to paste shell output, code, etc in than I am to need markdown features. What I'm hoping for, honestly what I really want, is functionality in Jira equivalent to the "Compose message in HTML format" toggle on email clients. "Turn off markdown in all my comments until further notice."
Doesn't mean I don't want to see markdown in other comments, just want to reverse the default to not use markdown.