Updating more complete dates and places in source attachments
Then a person in a family tree is listed, for example as being born in 1877 in New York, but a record suggestion comes up with the correct individual with a complete birth, mont day and year and or a complete birth location. Familysearch should allow a researcher to slide over the more complete and or more accurate information over. That would over write the old less complete information. we can do this when merging individuals, so it can't be all that hard to make a change in the programing., (Ancestry allows this. )
The way it stands a person has to remember what the source said and write in the corrected information. So often the correct information is buried in the sources and not updated in the detail view.