I tend to beleive that once you are heading into the 90+% for healing, its more about manipulating your raid to get high parses, not so much about “true” healing in a raid environment.
There is no need to put such emphasis on your percentage, but more to use your logs just to see where you can clean up your rotation.
I think people put way to much pressure on themselves to pull big numbers, when logs are SO much more than that.
How do you know if you are doing your job as a healer? Well….is your raid team still alive at the end of a fight?