maybe when the long-awaited update the notifications system is implemented, you’ll be able to get this. in the meantime, if you’ve turned off agreeing ID notifications, there’s not a perfect way to get back to those, especially since you have so many IDs.
to get the closest to your answer, you’d probably have to get observations from the API where ident_user_id=[you] and order_by=update_at. this will give you the most recently updated observations that you’ve identified. you’d have to keep getting results until the last set has observations updated prior to a date that you care about. then once you have that all those observations combined in one big set, you’d have to parse through the identifications for each observation, and you’d probably filter for just the observations where the last identification is not yours (or something similar to that, such as where there is an identification or comment after your identification).
then there’s the question of how you want to display the information…
i’m not aware of anything existing that runs a workflow quite like this, but if you can code, could do what i’ve described above to get your answer.
i wrote something the other day (Python) that might have the bones that get you very close to the what i’m describing and would just need to be adapted in a few key places. it’s still a work in progress, and i was planning to overhaul some of it to make it more efficient, but what’s there right now should still work. (see the link in the original post in this thread: https://forum.inaturalist.org/t/whats-the-best-way-to-share-python-code-nowadays/48554).