If it is large tomatos you want Brandywine isn't the right variety. You will want to choose plants with the genetics for 2+lb fruits and push those for max size.

It's like trying to get a jack o lantern pumpkin to compete with the giant pumpkins in the fair. Isn't going to happen. Sure, you can find ways to make the Jack O Lantern large for a Jack O Lantern, but it just doesn't have the genes to compete with the really big boys.

If you like heirlooms Neves Azorean Red has produced well and makes tomatos approaching softball size for me and I do nothing to try for large maters, it is just what those do. One slice covers an entire sandwich. They taste pretty good too.