Since the project is not done and on the bike, you don't yet know how this will affect your turning. The handlebars come really close to the tank in factory condition, this will mean the bars will contact the sides, I'd imagine.
I wonder if making the tank taller would have been a better way. The center of gravity might be affected going the tall route but you can't have everything.
Any real effort to increase fuel capacity deserves a definite applause to the tinkerer.
Many people are waiting to see how this turns out since lack of range affects us all.