I rock it like that. It works and I love the carry handle. Practical and solid rear sight. And I did not experience a zero shift with my holo.
Even then if you lose lets say 1 MOA.... At 50 meters 0.5" will not make a difference on a "combat" carbine. It's about been fast and robust and been able to use back up irons if needed. Pure precision under 100 meters at a section level is not a concern. Effective fire is. And .05 inch will not make the difference between effective and non effective fire. Heck, effectiveness with a C7 at 300 meters on a section attack level will not be determined by a MOA poi shif. Sharpshooting and pure presicion is one thing. CQB is something different. Not saying precision is not important but I hope you get thee idea.