Hm, good point; INSEAD does prefer to see IRs at or above 6; however, it can overlook them when other elements are strong. Indeed, if your heart is set on INSEAD, then it could be worth it to retake, but we know very little about the rest of the components and profile from the initial question, so...let's put that as a maybe. I would still say the overall score and quant component matter the most in b-school admissions at top schools, especially if testing opportunities have been limited in a pandemic. If a candidate only got to take the test once online, and got a 760 and a 51 quant, for example, and was looking at INSEAD but had a 4 IR, and he or she asked: could I apply to INSEAD? I would say yes; but if the goal, for example, was consulting, then you could comment about the IR score in the optional mitigating the lower performance with some counter-balancing info about your problem solving skills at work. Really depends on the situation and the rest of the components and the story though. In practice, I have not seen middle of the road IRs and AWAs be dealbreakers on their own unless there are other weaknesses or questions that it would raise (like a very low AWA for a non native English speaker with beautiful essays would possibly raise a question). So - there's a bit of nuance to this.
I actually hadn't noticed that the title points to a 720 overall score. That score is the one you want to watch - though again, there's nuance and it depends on your story and profile, but for some top schools, a 720 is below the average - a retake would likely be worth it, especially if you are in a highly competitive category. It might depend on your profile, though, how urgent this need is...and when you are applying. Right now, it is a very challenging application cycle, so I am hoping you are not aiming for R3, but talking about next year; but there may be continued pressure on applicants to bring their best to the table so a retake in the current environment could be wise. A 720 tends to be right around Haas's average, but if you are in a popular category, it would be helpful to try to be on the higher side of this. Good luck!
Julie-Anne