dfk41 As for retention, virtually every coffee served in a cafe/restaurant/mobile cart the coffee is ground on a hopper fed system.
We have discussed this to exhaustion, oblivion and to death in the past :-) - You’d think that in a busy cafe they are constantly making coffee - so you could argue retention is not a problem. If the grinder has been idle for a while, they just purge. Not a big deal.
I make two coffees a day, 6 hours and 18 hours apart. :-) - Wasting 37% of the coffee I consume is not an option for me. (i.e.: a purge of 7 grams or so prior to each session).
I am also having caffeinated coffee in the morning, decaf in the afternoon. So the hoper fed system doesn’t work for me.
If it works for you, then great.
