Strange adjustments and adjusting completed goals

So one of my first beeminder goals is/was words written for my thesis. Two weeks ago I noticed that I had underestimated my ‘total words written’ goal and tried to adjust it while leaving the target date the same. Strangely this resulted in a flat stretch being added followed by an enormously steep road. Retroratcheting got rid of the immediate flat stretch, but the steep road remained - and then went flat again from reaching the goal until the due date.
So this week was a bit crazy and I found myself reaching for low hanging fruit and counting generously just to ‘write enough’. But that aside I’ve now reached the adjusted goal a few days ahead of the originally entered due date - now I want to adjust it to a new goal and due date but I don’t want the road to do make its own decisions about steepness and flat stretches again because that completely undercuts the effect.
Should I just wait until the previous due date (to avoid interactions with previously entered adjustments) and change it then? Adjust and contact support if it turns out differently from what I intend? Create a fresh goal (for the same thing, basically)?

Email support with the details of what you want the road to do, they can edit the road for you.