Add a place/reminder to paste the YouTrack issue's ID and title in PRs
This is easily obtained (with the ID as a link, even) by clicking the "Copy ID and summary to clipboard" icon beside a YouTrack issue's ID link, near the top-left of the page when viewing an issue in a sufficiently-wide browser window, and it seems worth including.
Changed (non-breaking)
Separate the PR template "Changed" section for breaking vs. non-breaking
Simplify the wording of the checklist to simply say "Tests...", not specifically "Unit tests..."
Added
Changed (non-breaking)