Had an hilarious TAR. The API for the Soft Coded Legislative (SCL) flexfield, specific for the Dutch legislation, was missing. Advise was to use the core assignment API to load the assignments, and use the forms interface to add to those assignments the SCL defaults. And this for 100.000 assignments...
I had to repeat tree times that this was not really feasible over here, and to escalate the TAR, before they saw the light.

Having a dedicated SDM in Oracle support really helps you further. Now we should have the missing API within one week.