I have an IQsmart 2 it deivers 4300 ppi and is as slow as molasses in winter - ie it takes forever. But the result is outstanding. I believe the IQsmart 3 delivers about 5500 ppi.

If I run at 2400 ppi times aren't too bad but it certainly isn't even close to being fast. If you have thousands of large plates you'll be scanning for a few years. The good news is that if they're 8 x 10 plates you can mount two plates and scan overnight so I guess you might get 4 to 6 plates scanned a day if you run 24 hours a day. The machines were built to scan all day every day so if it's in good condition I don't think you'd wear it out. Epson - Ha! Buy a few of them. it isn't what they were built for.

I think some form of scanning with a good digital camera will be the only way to do the job in a practical timeframe.