For my second muslin of Simplicity 3697, I went ahead and lengthened the bodice front top and the front band.
Frankly, I'm not sure if it is an improvement or not.
My initial response (after trying it on at 1 a.m. last night) was definite fail. But looking at it this morning, I'm not sure. It seems to look a little droopier in the cup area and I'm wondering if I should go back to version 1 and experiment first with just doing a bigger FBA on the top. I may still want to lengthen, but version 2 makes me think I may not need to if I make the bust area in the top section more roomy.
I think my next step will be to go back to version one and do a bigger FBA on top and see how that looks.
Lots of trial and error... hopefully it pays off!