I've grown Brandywine. They are huge 1.5lb beefsteaks. They are indeterminates so you should certainly get more than 1 truss. Being heirloom, they prone to all sorts of problems.

funnily enough my cherry ones 'Rosella' are doing this, this year too. so we have left a side shoot to become another leader etc. last year it performed beautifully and grew to the ridge of the greenhouse.
this isn't a heritage one either. One of our heritage ones [from 1890's and is banana cream] has been stable for the 20yrs we've been growing it.

Thanks for that.

Honestly, I wasn't thrilled with 'Brandywine' despite all the rage. They are prone to various problems and for me it was a losing battle - blossom end rot was the worst. Maybe I got 4 tomatoes before it keeled over. I thought Money Maker was good, Mortgage Lifter was good, Kellogg's Breakfast yes, Box Car Willie is very good. For cherry tomatoes - Sun Golds & Sweet 100's.