I think there's not a definite answer. It depends on the coloring technique and overall style you want the end result to look like.
If you want a more airy and painterly look then I think that could work. If you want something really polished and defined, then it might still need some work to smooth out the shading, reinforce some of the edges that get lost and maybe give a bit more love to the background.
That might not be as big of a issue if you are planning to paint with opaque colors on top, but if you're going through the trouble of making a value painting first you might as well take care of everything before adding colors. But again, if you want to go for something painterly I think that can work as is.
Whichever way you go though, I would fix the part towards the top left. I guess you might have increased the size of your canvas as we can see a sharp angle there. It just need to be blended a bit better so that we don't see it anymore. 
Overall I quite like what you have going on, so I look forward to see the end result. It should be really nice 
