The waiver is the entry condition. Signed in advance it takes seconds; collected at a desk with twelve children waiting it stops everything, so moving it to the booking form fixes a queue that no amount of extra staff will.
Marshals set the capacity. The number of people on the course depends on how many staff can watch it, not on how much space exists, and a busy Saturday is exactly when that gets forgotten.
Inspections have dates attached. Padding, anchors and landing surfaces are checked on a schedule, and a dated record is what a park needs the day somebody asks what happened.
Near misses matter as much as injuries. Recording the fall where nobody was hurt is what shows a pattern on one obstacle before it becomes a claim.