It seems to be correct. In the help I found for the calculation for the correctly predicted match result:
full points plus two times the goal bonus for the correct amount of goals for the home team and the away team.
total = 5 + 1 + 1 = 7
With the extra plugin also the the points for the goal diff are added, in my case it’s 1 point.
So the total score becomes 5 + 1 + 1 + 1 = 8.