I would defiantly keep the plant tied down. It enables nearly every branch to develop into main colas. You will be surprised to see if you take the training off, in a week of two the plant will have lifted the branches back up to nearly where they started.
I would not pull down any more though, just let what you have grow up.
It looks like really good job of training and I would keep it 100%. Kyle Kushman (The godfather of LST) would be proud.