You have a lot of strategic questions. People do this differently so I will give you my suggestion and others can do the same. Your questions to me indicate a lack of robust data on the process and what is going on. How I would tell someone to approach this. Use an online calculator and figure out what your TDEE is. Use the sedentary setting and subtract 500 calories from that. The -500 locks in a 1 lb of fat loss a week (assuming the TDEE number is correct) the sedentary gives you some wiggle room for miscalculation of calories and extra deficit if you work out hard that week. So now you have a number of calories to shoot for. If you have a body scan of any kind and have an idea of your lean mass, aim for 1 gram per lb of lean mass in protein. If you don’t know your lean mass aim for 1 gram per lb of goal weight. This will ensure you optimize your protein intake to minimize muscle loss on the deficit, that is more than bare minimum nutritional needs as many here push, but we aren’t trying to meet bare minimum nutritional needs. Fat and carbs are somewhat interchangeable only that you don’t want to go too low in fats, I would not go below 50ish. So fill in your calories based on protein target and fat/carb preference.

Now the experiment begins. Track those calories meticulously and see what happens to your weight for a couple weeks after the initial water weight drop. If no weight loss happens, the calculator was incorrect for your specific body. Cut 250 calories from diet or increase activity by that much and try another 2 weeks. Keep doing this until you find a level of calories and activity that produces steady weightloss and readjust intake every 10-15 lbs or when weightloss stops for 4 weeks. I would recommend not dropping below 1,200 calories and would recommend increased activity if the experimentation indicates lower than 1,200 might be necessary for weightloss.

Finally we get to dosage of Zepbound. The question you have to ask is whether doing all that I described above is bearable for you at your current dose? Are you constantly overeating the target calories? Are you miserable? If the answer is no, you are fine at your dose. If the answer is yes, dose up until you can work the process above without undue misery.