I can see that other people have answered your question.
I just wanted to add a suggestion, which might be helpful.
I tend to write quite fulsome comments, and to avoid being trapped by the 5 minute edit cutoff, I sometimes write what I want to say in Word, check, edit, revise etc there, and when I'm happy, just cut and paste the whole thing into the comments section.
I have no idea whether your desire to change a particular comment is because of typing errors, or, for want of a better description, 'post-comment regret'.
But writing what you want to say, in a separate environment, can help alleviate both problems. I've certainly decided on more than one occasion, not to send a comment I initially thought I felt strongly about. Nobody but me any the wiser.