Should answer your question regarding the application not sending Additional data.
Then happy to see this initiative as after lot of interest last year I gave up trying to clean manually since it seemed an initial automatic clean up could be performed as you demonstrate (difference in number of sources, huge difference in duration,…), May look tough but honestly just removing all with less then 2 or 3 sources may help 
Or as since it was reported those errors are mostly due to people who sent massively their collection without checking maybe those could be identified and removed.
PS: Removed = totally removing, not just unlinking in order to clear the pages and as in case it was legit, a new fingerprint upload will make it appear again whereas when it s unlinked it wont. This behavior may seems strange but is actually useful for similar prints ex: the silences on https://musicbrainz.org/release/04c77734-4d5c-4b91-bd0d-27be62f2e67b