Will all agencies respond to a request for processing notes?
Who knows? After all agencies are run by humans who make the rules and who also break them, either legally or not.
Cathie, hello! As with all things FOIA, it does vary agency by agency - the CIA, for example, is particularly notorious about this kind of thing: https://www.muckrock.com/foi/united-states-of-america-10/request-for-processing-notes-and-search-slips-for-foia-2014-00114-9231/ While the DEA was (relatively) easy to work with: https://www.muckrock.com/foi/united-states-of-america-10/foia-processing-notes-6835/#1086875-responsive-documents One advantage you have vis-a-vis an appeal is that you can use the responsive documents of other agencies - if they reject you outright, you can ask them to provide specific arguments and reasoning, and then ask why that didn’t apply in the cases of these responsive agencies. Hope that helps! J.Pat