It's raised in a recent Foundations retrospective that the questions in the "What makes this change safe" section of the PR template did not get good adoption, likely because the inconvenience of answer those questions - PR authors need to manually edit the template comment and put in the answers. Those checkboxes in other sections had a much better adoption rate as they are handy to tick. 

The improvement idea is to convert those questions into checkboxes in the PR template to drive the improvement for their adoption rate.