I just accidentally quit PM due to the stupid Chrome browser which doesn't quit in one Command Q, so trying to quit it with a second quit, accidentally quit PM as well instead. (Obviously, the worst possible UI mistake Google could make was requiring a double quit to quit.)
But then on reopening my contact sheet, which thankfully was properly saved as per my preferences, the behavior was extremely sluggish. Like a 0.75 second delay after rating each photo instead of a snappy, instant response like it was doing just 20 seconds before.
I checked Activity Monitor and PM has been reading files at about 200 MB/sec constantly for minutes. And continues to do so as I try to cull, which is clearly the reason for the sluggish behavior.
But I am currently on photo 21,000 out of 22,000. I have zero need for PM to be reading the prior 21,000 photos.
Shouldn't PM be preemptively reading photos **ahead** of where I am in the contact sheet rather than **behind** where I am? At least not to read photos behind where I am with such a degree of intensity that it slows down my progress in continuing through the contact sheet from where I was already?