When trying to upload some updated issues via the JIRA Excel plugin, it appears to download an entire project (thousands of records) and then scan them, searching for the records that have changed, rather than just downloading the records identified by the keys in the spreadsheet.
Under some circumstances I have not isolated yet, I get an error trying to upload that it could not find a given ID, even though that ID had just been loaded with the Load Data command.
Can I get an explanation of how this works under the covers that would help me to adjust the approach I am taking or set my expectations around how the plugin is intended to work?