Use repeatable batches instead of one overwhelming rescue attempt.
Older libraries, or ones that have moved drives a few times over the years, can turn up genuinely large numbers of broken references, history in particular tends to accumulate a lot of stale entries over time. Facing a workbook with hundreds of rows in one sitting is a good way to lose track of what you’ve actually reviewed.
Instead, work in rounds. Filter or scope a batch down to something reviewable, work through it properly, validate, import, and re-run a Healthcheck to see your progress. Then move on to the next batch. It’s less dramatic than trying to clear everything in one go, but it’s much easier to stay confident in what you’ve actually checked.