zenkovaelizaveta:
Responding to each of your points:
Q: How much does applying in R4 diminish one’s chances of getting accepted?
A: Fairly significantly. The numbers are not publicly available but there's an estimate that there are maybe 10% of seats remaining. Even if far fewer people apply, you're talking about very few available slots.
Q: I have same situation with GMAT now and am just wondering whether it’s worth retaking it or not.
A: You are better off waiting until the next year if you think you can really improve your score. A candidate's best bet is almost always to put forward the best application the first time including the highest possible score. If you are unlikely to approve then apply now and give it your best shot.
Q: Also, do schools mind how many times it took to reach the desired score? And if yes, how does it affect AdCom‘s decisions?
A: The general rule is try not to take it more than 3 times. Beyond that, it's technically acceptable so you won't be ruled out. It also depends on your progress, if any. If you hovered around the same score, the it probably won't matter. If you went up in score, then that could still work in your favor. If you went down, well that's probably working against you.
Hope that helps,
Admissionado