Oh, I would not only work. I would play very much in and with the water. How does the head position influence the balance, how does the arm position change the balance.
Switching from back to face and vice versa. In longitudinal axis and in short axis.
Paddling/ sculling with the hand in the water. How can I move calmly and get a good grip...
Body dolphin versus just dolphin kick. Kick from the knee versus kick from the hip drive.
I'm often playing with the water. Not really doing drills, just moving, enjoying and observing. Several weeks I was only "playing". I hadn't the time to go to the pool often and when I went, I went with the kids.
The first time after this "non swimming time" I was astonished how much I learnt by doing "nothing".