This sounds exactly like my Sage. Months or years will go by and I don't grow grass for her. Then I grow a pot of gras, she eats it then she barfs. If I didn't grow it, she rarely barfs. Then she is back to running and eating like nothing happened. Same thing as Zoey. . .sometimes there is a little bit of hair, sometimes no hair.
She has super short Russian Blue hair so she is not prone to hairballs. Her first hairball was when she was 5 and it was the size of a pea
Her biggest ever was when she was 10 and it was the size of my pinky
All the other "hairballs" were just little smudges of hair, not even in the shape of a ball.
I know y'all wanted to know the details, eh?
Anyway, Sicy, Sage is just like Zoey. If you want to offer her the grass, and not have to clean up, only offer her one blade at a time, and hang on to the blade so she doesn't gobble the whole thing at one go. I notice if Sage eats small nibbles1/4-1/2 inches at a time, and only one blade per day she keeps it down better.