@Chris, I did a catered event last night for over 100 guests and served 240 chicken soup spheres. Holding in the alginate bath for a longer period of time worked well.
This is a shot of the set up I came up with for large batch production. I can create 48 at a time using this method.
Held 120 fully made for speed purposes during the event while making the other 120 in front of the guests for the action station.