I don't have Carmine Monarch, but my Red Volunteer has not rebloomed. Like daylily, I don't get much rebloom here. The description of CM says it has a green throat, and Red Volunteer has a gold yellow throat according to the AHS site. Maybe you can distinquish it from that. Looking at the blooms posted in the daylily list here though, they look somewhat similar with RV being a little darker red.
