Down railed nose bottom shapes

I am working on a 9`6 with wide point a hint behind center, fat 50/50 rails from the tail and then fades to down rail in the nose.
Right now the board is flat on the bottom, would a slight concave in the nose work with the down rails?

Another thing while I am on it, how would you solve a too thick tail when a board is "done"... Is it too late to remove some thickness from the bottom and add some extra kick in the tail when the rails are done?

If anyone has some pictures on a board they like with down rails in the nose I would love to see how much down rail it has. I know Ace posted some pics but i cant seem to find them.