What is the general goal of the feature?
to use fingerprint within ODK.
What are some example use cases for this feature?
What can you contribute to making this feature a reality?
It's not, but if you search for fingerprint, you'll see that it comes up a lot. For this to be considered, it has to be filed at https://forum.getodk.org/c/features and the use-cases flushed out. One good first step is for you to file that request and link to the various threads over the years...