Some of us have several places to reload. I might do single stage 44 mag in one house and then another day on a progressive in another house. Same load.
It's good to know the scales read the same.
Like calipers and micrometers. I have a machinist friend who calibrates my good micrometers. I have miced and verified my NOE expanders so I can use them to quick check some digital calipers. Or as pin gauges,whatever.
Maybe OCD but I find it easier to know actual numbers.