Checkboxes in PR progress section to track items has these disadvantages:
1. On GitHub at least, these checkboxes can be clicked; PR authors may click or unclick them, unknowing that they are just render effects.
2. Links to PRs on GitHub (say #1342 links to #1243, the link "Xxx refered to this pull request in #1342") may show "3 items" or "4 items"; GitHub misunderstands these checklists as actual user checklists. This affects user experience.

I recommend changing these checkboxes to emojis, like the white checkmark in green box and the music player pause sign, to avoid these shortcomings.