That which is in the instructions to the jury is a critical part of the trial.
That "boilerplate" is argued over quite heatedly, as it matters very much (even just the wording, let alone which laws are cited) to both the prosecution and the defense. The prosecution and defense modify what they say in front of the jury to take advantage of beneficial parts of the instructions and to minimize the detrimental parts. Particularly in the closing arguments.
In turn, the judge needs to do a good job on the instructions to keep from giving cause for a retrial.