First thing to do with dosers is remove the automatic grinding which is really ease and then it's just manual.

My technique with the SJ was to pour in the beans and put a tamper on top of the grinder to prevent popcorning. Then grind and when it's done scoop out the grind out of the exit chute with a plastic spoon and purge again and all of the ground coffee will be in the doser. I then twacked the doser multiple times while usng a brush to sweep everything clean. It sounds like a lot of work but it's really easy and you've got zero retention.

When you use GOD grinders you, in general, don't have access to the exit chute as there's an anti-static screen and a big lump on the front of the grinder giving even less good access. This all tends to lead to aorund 5-9gr of retention every espresso you make.

A few years using a Mazzer Mini. Then almost couple decades of using a Macap M7 until a few days ago. Single dose using a diy single dose hopper and popcorn reducer. With the fingerguard removed using a brush and thwacking the doser lever while grinding most of the coffee in the chute is emptied into the doser. Using the same brush to clean out most of the coffee in the doser. Ideally need to do a small "sacrificial" grind to clean out the coffee stuck in the burrs.

Broke down and purchased a Niche Zero. Not sure how many kilos of coffee have been wasted over the years. Really appreciate the simpler, smoother, quicker, cleaner work flow using the NZ. Don't really notice any improvement in grind quality. Both machines are conical burrs. The M7 I think has an 83mm burr and runs at ~400 rpm.