Remember that sleep is extremely important for everyone, especially us neurodivergent folks. I would not recommend taking any stimulant past noon. Hell, I struggle with sleep as it is and I take my ADHD medication at 6 AM.
I have a feeling that you’ll adjust quickly and need to up your dosage to get any effect. I find that my body adapts very quickly to medications, especially stimulants. Unfortunately, that means building a tolerance over time and requiring either a long break or upping my dosage.
I’m not a doctor, so I can’t give you advice on dosage. I just wonder how you’ll measure it.
The evidence that I’m aware of suggests that we with ADHD process caffeine differently, but it still has an effect on the brain which can affect one’s sleep. I drink caffeine in the morning because it helps me calm down and focus while I wait for the medication to kick in.