I've had Hashimoto's for more than a 1/4 century. Absorption issues have never been a significant problem. When I took Synthroid, I'd take it in the AM prior to breakfast, with some water. Then shower and eat afterwards. About 30 minutes from taking the drug, to eating. When I traveled, I'd take it when I could, often in a rush to wake up, eat and leave the hotel. My labs were steady for decades. Nor did I notice any improvement in symptoms if I was exceptionally careful.
Because the Half Life of T4 can be almost a week, if absorption is great one day and less perfect the next day, the average levels day to day may not change much. With any form of reasonable consistency on your part, the lab levels should remain in the upper 2/3 normal range.