Success with the green bag, that is good to hear! Good for you!
We feed the green bag small bites here to seniors and young'uns. Morning add-ins include sweet potato and something green (beans, zucchini) or carrots for the young'uns, and turkey/scrambled egg for Seamie; at night the add-in is a home-cooked stew for everyone. Their poops have never been better. Foster Sweet gets a different type of kibble and I can tell you ... there is no difference between large and small kibble pieces ... the speed of inhalation is the same
Good luck, I hope the green bag continues to do well for your pup.