It doesn't avoid the delays. I have incredibly fast CFx cards, an incredibly fast card reader, and an incredibly fast CPU in my desktop, but the simple reality is that reading tens (or hundreds) of gigabytes over USB takes a long time, and analyzing those files to determine if they're already in my large photo library takes a lot of resources too. Minutes, not milliseconds.

A RAW file from a Nikon Z8 is generally 50-70MB. If I left 300 photos on the card before going out for a shoot, that's tens of gigabytes of data to transfer and analyze before the software can get to the images I'm actually interested in. If it's hundreds of gigabytes the problem is even worse.