Yes & no, its really down to experience & how you like fo grow. You should take them off in very small stages if you're going to.
These are autos. So I tend to wait until they've fully grown and as it goes into its stretch before actually going into pre flower. You can take the biggest fan leafs supporting the fully grown nodes. Remove 1 set each day..you'll know about 4-7 days when your plant is going to flip. Therell be a massive stretch and you'll see lil hairs where the nodes break away from the main stem. And other places. Defoliation is perfect to do at this stage. As u know its flipping..as doing defols on autos can induce stress which can cause a premature flip.
Small stages, big old fan leafs. As the purpose of this this to transfer the energy into the smaller leafs developing on the nodes themselves.