Spoiler, its RDT
In case people do nto know what RDT is, which they really should if they have been into coffee for a little while as it makes a big difference:
RDT is Ross Droplet Technique, which is very much adding water to beans. Named after David Ross who came up with it back in 2005
So the goal is to make your “ideal” shot for the beans you have. Reproducibly. So right off the bat if the ground weight out isn’t equal to the unground weight in (as close and reproducible as possible) then you’ll have to adjust other factors for each shot. Which can quickly become extremely complicated. Especially with static where the amount of loss is going to vary every time.