Hi, I was reading through your post. I'm wondering if there is a history of allergies or allergic reactions on either side of the family. In the case of a food allergy your baby can exhibit some symptoms that mimic oversupply issue symptoms. Green poop, gas. I would take a close look at your babies bottom. See a red ring around babies anus after a poop? Could be a reaction.
I have some thoughts on pumping right now. If you are having an oversupply of milk, every additional time you pump you are sending a signal to your breast to manufacture more. More and more and more. As the people said, the objective is a good balance of milk, not all one or the other. Too much milk means your baby has to eat through many ounces of surplus fore-milk before the fattier stuff can be absorbed. Even when you pump after a meal, like you said. I would consider gradually weaning back on pumping, pump off the top for discomfort to avoid becoming impacted, but not to clear out the breast. While I understand your desire to have milk in storage for work, it is no good to you if the removal of the milk causes your baby problems right now.
Can you tell us the length of time you used, when you tried block feeding?
When do you go back to work?
Have you explored the allergy forum yet? Look at the list of allergens. The main culprit is often dairy- grass protein, is what the real problem is. If you try eliminating it from your diet be prepared to look for hidden dairy as well as the obvious stuff. It takes approx 2 weeks to clear out dairy from your diet.