I see no reason why coffee dose in a Robot should be defined differently than any other machine type. It depends (IMO) on the bean, and one's taste preference. I've pulled coffees were a 1-2 ratio was perfect, others where a bit less output...say 1-1.75 was preferred. Even then, the actual grind weigh played into that. In other words, my current coffee likes a 17 gram dose, 1-2 ratio. But another likes an 18 gram dose, the same 1-2 ratio.
One of the Robot's strength for a "lever"...the 58mm basket, makes it easy early on...after a few shots, to dial in the dose AND ratio. For ME, easier than my previous 49mm machines. To be fair, the wonderful Strietman CT1 (49mm) was more forgiving.