Agree, it's pretty cut and dry but CDC's thirteen FOIA employees seemed unable to handle it. Judge disagreed and told them to do their farcking jobs:

Having reviewed Andoh’s declaration, the Court does not find it ultimately persuasive. Instead, this Court finds that production is not unreasonably burdensome for at least four reasons: the requested records are not so voluminous; only a small percent of records will require any redaction; the redaction process is largely straightforward and capable of automated assistance; and blanket exemption claims covering a mass of records are impermissible.

I wonder if the fastest way to remove the PI would be to cut out all the meaningless words, leaving just the records with numbers, names, etc. Seems like a task that you could never do perfectly (e.g. if a user were trying to encode their PI they could probably do it), but would at least be a good faith effort.