We use the Workshop quite a lot and love it. (In Moodle 3.10.1+ now.) Kudos to David for contributing such a great activity.
I believe that the 80/20 maximum grades are a kind of legacy from old gradebook set-ups. At my centre we tend to grade everything out of 10 and use the "weighted mean" aggregation in the gradebook to adjust weightings. This system makes the gradebook more easily comprehensible to students, in my view, since good and bad grades for individual items are plain to see.
With this in mind, we tend to encourage teachers to change the 80/20 maximum grades in the Workshop to 10/10 and then they can weight the grades in the gradebook, if desired.
As a system admin. can I change the 80/20 default setting for all users? Are these values hard-coded?
If I have to hack the Workshop module to change these values, where are they?
I am guessing that I just have to change this in settings.php.