One reason I decap (forgot that) and tumble before flame annealing is to remove some of the lead residue.
I use a 21 Century primer
I also use a Chargemaster Supreme. Probably my biggest gain would come from moving to a better changing system like the FX-120i but it is not in the budget right now.
I already spend far too much time reloading. I’m trying to be very careful about what I add to the mix. I don’t weight sort my bullets or cases much less primers, so there is that too.
I don't worry about the lead residue as I minimize contact with the small amounts of lead wearing gloves when I clean the necks with steel wool. And I really don't want to remove any or just remove very little residue on the inside of the necks. The order of my cleaning takes care of the inside of the necks very well, minimizing interference to where running a mandrel through the neck and seating is quite smooth and consistent. But, I can understand one's caution about contact with lead contaminated things. Maybe I should wear a respirator when reloading or even when shooting???


I like the different smells of burnt gunpowder.
Yeah, I'm sure upgrading to a better scale would produce a significant gain in SD's for you. It did for me when I move from my ChargeMaster to the FX-120i.
BTW: Besides sort primers and bullets, I also tested sorting cases by weight and found that too really does help, where one simply removes the outliers and just using them as fouling shots. I took the sorted cases and fired them in groups having either the same or close to the same weight in a series of shots. I also compared 5 cases from each end of the sorting to see what kind of difference there might be and found it was significant. I did this with my .308 fire formed Lapua cases uniformed before weight sorting.