I've heard that it is possible to search pacer.gov to find all affidavits authored by a specific expert. But I cannot find that function on the? I did not find anything on this in this training manual: https://www.pacer.gov/documents/pacermanual.pdf
I run the RECAP project at Free Law Project, and spend a ton of my time in the guts of PACER and CM/ECF.
I don't think it's possible to do what you're asking. The only idea I have is searching repositories like ours, where you can do full text search for an expert's name.
Wish there was an easier way, but PACER is...not the best system.