Rear irons on carry gun?

I have one of the new breed of sub/micro compacts (S&W CSX) and recently found one of the only shops that is starting to offer optics cuts for the model. Caveat is the size of the slide does not allow for retaining the rear irons with any optics and when I inquired they said they don’t really see the Holosun K-series as a truly preferred alternative because the built-in notch on that optic will not align correctly. This has me thinking if the rear sights are truly a necessity on a carry gun with a well-vetted optic like an RMRcc. I know some OR sub/micro compacts have their rears built into the cover plate so you lose them if you put an optic on. Just curious on where the sub stands on the topic.tl;dr are rear irons a must-have on a carry gun with an optic? via /r/CCW https://ift.tt/qi4wnZ1