When to take top up? Vyvanse and Dex

Just curious to see when you take your top up? I have 60mg Vyvanse around 8am and start to feel it wearing off around 12 which isn’t very long for something that’s meant to last all day. Anyways I push through until around 1-2 then take 5-10mg of Dex.

Just curious to see what other people do, I’ve found that taking my top up too late in the afternoon results in awful insomnia, literally won’t be able to sleep until 5am it’s horrendous.

How are you taking your vyvanse and Dex? What’s worked for you to help with sleep? I recently cut out caffeine and trying to not have so much sugar in the afternoon.