I not had answer from our dell contact but we try on our side.
It seems for the moment there is no additional cost for this process.
Our test are limited to one device for the moment and it seems working. We try the random password. We need to wait around 30 minutes before see it instead of null in the graph api request.
For the moment we have 2 remarks (questions):
-What happened if we wipe a device and enroll it again. I think the password will not change on BIOS. And the Intune BIOS configuration probably not working for this one. It could be good if a wipe delete the password too. Maybe a new settings in the configuration?
-We use Azerty keyboard (french) and it could be hard to type the password that use special characters. Is there a solution for this?