Rich, how've you been? All the plants you gave me last year are also pretty tall. All are doing well, some are in the ground.
Consensus seems to be about 18", which would work out nicely for your tall plants.
At the end of this Fall, my plan is to cut everything to that often prescribed height, which will guarantee me backup cuttings, and will also make the plants easier to cover for the Winter.
You may also consider an air layer if the plants aren't fruiting, or don't seem likely to ripen fruit some 6 or 7 weeks before the cold sets in.
You should read 'The Kadota Fig: A treatise on its Origin, Planting, and Care' by W. Sam Clark.
It's a pretty old book, so it's easy to find it for free online.
Within the first few pages there is a good bit about planting and pruning, with great photos.