Hello,
When the sail is down, you can use the topping lift (as long as you slack the main sheet and vang) to raise the main as high as you like. Raise it up so no can bump their head on the boom.
When you raise the sail, you should slack the topping lift so that it is not holding the boom up. The sail will hold the boom up. Now you can trim the sail with the main sheet (and vang when sailing down wind).
If you have the topping lift on when the main is up, you won't be able to trim the main when going upwind.
Good luck,
Barry
When the sail is down, you can use the topping lift (as long as you slack the main sheet and vang) to raise the main as high as you like. Raise it up so no can bump their head on the boom.
When you raise the sail, you should slack the topping lift so that it is not holding the boom up. The sail will hold the boom up. Now you can trim the sail with the main sheet (and vang when sailing down wind).
If you have the topping lift on when the main is up, you won't be able to trim the main when going upwind.
Good luck,
Barry