I reload on a RL 550, so everything is the same (vibrations, etc.) in the loading cycle when I take out the cases with powder to weight the charges and check the consistency.
I have even checked the effect of the powder level on the measure (it has only one baffle at the bottom, no extra ones), with small grained powders there is zero effect as long as you are one inch or more above the baffle.
With small grained powders in my Dillon RL550, I get close to exactly the same weight every time. Perhaps one or two throws in ten is 0.1 grain off, measured carefully with a balance beam scale.
None of this matters for "normal" shooting, the pistol will group almost exactly the same (and POI will normally be the same) at 25 yds with some rounds loaded with +/-0.2 grains of powder.
I'll often throw 10-20 charges and then weigh and divide to get an average when setting up the powder measure on my 550. If you go by any one individual charge, you'll be chasing tenths back and forth forever. Perfection is the enemy of good enough. Consistency helps a ton for sure. I usually toss the first 10 throws back in the hopper, if it's been sitting for a while, or after refilling, just to help things settle to "normal" during operation.