You use it if you're off of the delay you want. Like you're trying to hit 687 and instead you hit 681. You type 681 into the box and hit update. This will adjust your calibrated delay accordingly. The idea is that you'll hit more consistently and you wont have to change your delays for anything.
It can also be used to skip the calibration process. If you use the defaults and use +/- 99 delay on RNG reporter, you can quickly find your calibrated delay without having to catch high level pokes.
v1.6 - oh so much. | v2.21 - efficiency update
<Mat> everyone should get toast's opinion on everything beforehand
<Nexus> we've awakened the devil in Toast