There is an allure when they are small and young to get the branching started early, but what I am finding is with the full spectrum LED lights the nodes are close 0.5-1" and the leave are on the smaller side. This means the low older node sites get hit with plenty of light and branch a lot naturally. If you FIM with intense DLI you can end up with a bunch of nodes all within in 0.5-1" which makes it a pain in the ass to manage. Instead of FIMing or topping I think it might be better to bend the seedling over as soon as you can so you get an early horizontal runner that you can start branching off while taming that first top down as much as possible. Here are bunch of plants that are 28 days old now. The ones that were topped properly are so much easier to manage.