SHUT harsher so door locks tight:
Use a small flat screw and turn TOP adjusting screw…COUNTERCLOCK WISE, 45 degrees at a time, to make the spring tighter so door shuts faster at the ending 20% of the movement. Test by opening door before you turn the adjusting screw again.

To close slower so it will not hit slowerwalking people: Use a small flat screw and turn BOTTOM adjusting screw CLOCKWISE, 45 degrees at a time, to make the spring loose and slower the initial 80% closure part of the closing process. Test before you turn the adjuster again.