There's a related
thread here.
I don't have any inside knowledge, but I would expect the solution will be to allocate points based on final qualification ranking rather than average scores directly. Average scores always increase through the season.
By design all district events have the same number of qualification matches, so the average number of qualification points is fixed across all events
1. This is even more important with the introduction of inter-District play this season.
1 Almost constant. Disqualified teams (no shows, not inspected & red cards) do decrease the average qualification points across events