Allowable backlash

Anecdote;
You know what grease is?
It's oil and soap homogenized together. Ergo; soap and oil/oil and soap;lol.
If you let a dyno wheel-bearing grease sit in a warm enough place, for a long enough time, the oil will separate out and float to the top.
IDK about synthetics.
Well that's how it used to be when I was younger. I can't say if that is still true today. But some of the greases in my shop are older than am I ..........