I use a scale with a resolution of .001 reason being no matter how accurate a scale is they have a tolerance on the load cell a scale with a .1 reading typically has a tolerance of +/- .1 a scale with a .01 readability load cell accuracy is +/- .01 my scales load cell accuracy is +/- .002
So a scale with +/- .1 actual can be .2 grains difference but I've also found that not be case it can read say 32.0 grains and weigh it on a precisin scale and it'll be off as much as .3-.4 grains. Scales that measure .01 real readings can be off as much as .04 grains so a scale that will read out one more decimal only assures a bit more accurate charge. The scales that read .00 places are excellent for what we do as in reality we can't control our powder that close if using stick powders. One kernel of Varget is .02 grains H1000 is .04-.05 H4350 is .03. The only way to get exact measurements is using a very fine ball powder.
I don't shoot point blank competition but I am aware ES and SD is a none factor for you guys most will agree and your groups and aggs prove that. You guys are much better at tuning I think say than us long range shooters, but we load more precisely over you guys is because we have to we need single digit ES and SD and we need our charges to be within +/- .02 grains of our target load. I've tried my best to hold my loads to exact or within .01 grains or +/- .005 and its just impossible to do such.
Think about it if using Varget and each kernel is .02 grains and a scale has a resolution of +/- .1 or a total of .2 grains over all that's 10 kernels of powder.
One more thing if you're using a scale that reads down to .01 grains unless you have it on a line conditioner where it cleans the power and puts out the exact amount of current each time you're just wasting time on weighing your charges on those scales.
I'm sure I've not said anything here you guys already don't know or are aware of, maybe some don't realize the accuracy of a load cell and you won't unless you have a scale that will weigh charges down .001 grains. My numbers given are from my experience using a chargemaster also a DI scale that reads .01 and a DI scale that reads down to .001 but I'm no expert and many here knows more than I'll ever know. I just know what works best for me just as you all know what works best for you. That's the most important factor in my opinion. The rest is luck and able to see a switch in wind most don't see.