"I have not seen a way to force it with valence"
Awww....
"You half to configure the system to export the final adjusted grade instead of the calculated grade. This is done with the d2l user interface in the gradebooks options"
You also have to get the teachers to remember to set up their gradebook that way, and to transfer the Calculated values to Adjusted Grade results within the gradebook. Some of them will forget to do so.
Don't forget, those Valence calls for "/grades/final/values/" are pre-release. In other words, it's quite possible (using Valence API) to retrieve the calculated/adjusted values before the teacher has officially "released" them for students to view. In short, your Valence calls may be a bit premature.
What seems to be missing in Valence is a call for
"Get Final Released Grade" - the same value the student would see (when it's been released).
The decision for Calculated Vs Adjusted would have already been made by the teacher (in the process of releasing the grades), and no results returned from the call (ie: a 404 error) until the teacher releases those grades.
I wonder if there's already a Valence API feature request for that?