Wrenkins, I probably could make it more rigid, but that would not solve the excess ease at the dart tips that would still be there and doesn't look too good.
Missie, unfortunately I cannot extend the tucks that incorporate the bust darts, as that is how the pattern is made. But I could try extending the other ones as they are made to end at a seam (armhole/shoulder).
BrendaP, you're right, a much thinner fabric that would press well would be very different, tho it still has to be topstitched (I made a test version out of muslin but had the same problem with thegaping tucks). I did interface the scuba so it's a bit more rigid and holds a crease well, but no matter what I do I don't think I can sew a dart with a very smooth tip.
Well, learned a few lessons at least
And the scuba was rather cheap, so not that sorry about it. But it did consume the last of my interfacing, and that I'm a bit sorry about.
How about some form of decoration to hide the dart tips. Maybe some applique or something? Tho I'm not sure how I could do that without attracting more attention to the area? The only thing I thought would work is to apply some ruffles (maybe in organza and in the same color) in princess seam shape. But I'm afraid that would be a bit too much.
Something like this: