Dan John has written about this some, and while I like a lot of things from the man, my feelings on the matter are somewhat mixed.
I think that it can be a good idea in the sense that it kinda cuts the bullshit and keeps people from worrying too much about micro-jumps when there’s little difference in the training stimulus between squatting 275 pounds versus 280 pounds, but I also feel that, in my personal strength journey, several times it has been valuable to take some smaller incremental PR’s, if for no other reason than the mental boost of hitting a “PR” on a given day.
My deadlift PR over time has gone as follows:
There’s something to be said for Dan John’s school of thought, which is that after hitting a milestone like 455, you shouldn’t re-test your max until you’ve built a reserve amount of strength such that you’re ready to hit 495, so it would be fine to do all of your training with 365/405 (or even occasionally 455) until you are ready to go at 495.
My brother has started lifting with me on Saturdays after a long (>5 years) layoff from barbell lifting. Right now, hitting a new “PR” every week seems to be fun and keep him engaged, so I like having the small plates around for that purpose. He’ll hit a 5 or 10 pound PR almost every week for the next month or two, I am guessing. Once he’s squatting 315 for a couple reps, then maybe we’ll settle into something a little different.