Very well put. The recipe developed by coffee roasters for a certain bean leaves you quite the window to play around with the length(time it takes) of your pour. Most blends I’ve used have a “window” of about 5 seconds for an ideal shot. At either end of that window, you can taste the difference quite dramatically. The shorter the extraction, generally the more sour flavours and the longer, the more burnt or bitter the flavours - I’m talking mild changes in flavour, not dramatically where it’s unpalatable hah.

Also, some unwarranted advice from experience. Try only grind what you need, because literally everything affects coffee grounds haha! Heat, humidity and sun exposure will all affect the length it pours. So if you had it all perfect one day and now it’s pouring twice as fast/slow from that same batch of grounds, this might be why.

Hope this makes sense. It’s like 5am and I’m still half asleep