How many grams of espresso do you use in the single basket from ECM and what other techniques lead you to successful and efficient single shots?

When I make shots in different basket sizes, I usually want as much output espresso as possible. So I fill them up till the puck is not disturbed by the shower screen when locking the portafilter into place. That sets my maximum mass of ground coffee.
Now using light to dark roasts will change the volume in the basket. That's the nature of roasting. Dark beans create much more volume for their weight.
So there's no one answer. It's best to start off with one roast of coffee and stick with it till your pours work well.
The worst thing I did was try 3 different roasts / beans with my new espresso maker. The weights will be all over the place and frustrating to pull off.

My single shots still are a favourite for a change of taste.

Dave