What I mean is that some baskets have a reputation to work best if you stick to the rated dose within 1 gram plus or minus. If you get good results with lower doses and finer grind, by all means stick to it.
I use a Strada basket rated for 17 grams. The head space of my machine doesn't really allow higher doses. In fact, the spent puck typically has a slight imprint after the brew cycle when I dose 17 grams. I talked to a local supplier of these baskets and he suggested that to minimize the amount of fines in the cup (which were slightly bugging me at the time) I should try not to underdose and rather have the puck just touch the screen. If I come across a coffee that is really bold, I sometimes switch to a 14 grams basket that I can updose to 15 grams, but overall I am happy with what I get using the 17 grams Strada.

Hi DeGaulle,

I'm not getting more fine grinds in the espresso with the 22g basket @20g than using the 20g at nominal capacity. Below is a pic of what I've got in the cup

I've also checked your best practice to flush for only 2-3 seconds before shot and based on a minimal 2-3 shots, they were clearly a tad bitter. So I guess I'll stick to my method, that is, to flush until steady flow, then watch boiler pressure to overshoot and then settle and then pull the shot. This way it's very consistent.

That looks quite OK to me.
I mentioned the fines because I had quite a few in the cup when I started out with my stock basket, which was my prime reason for trying a precision basket. With my 14 grams LM basket fines in the cup are second to none; the 17 grams basket has slightly larger holes and leaves a tad more fines in the cup, but I stopped being bothered with it.
Good you sorted out the dose AND the flush routine that work for you, that is what counts.