In reply to GLUF:
I think you'd be doing very well to determine which holds were in and which were out, as you climbed. Better to work out from the deck what ones you can use. Personally, I think it'd be a poorer training option than just doing a single-coloured route, pre-graded at your target F6b.
Yes, you could do it the way you suggest, but I don't think you'd get much benefit from it, if any.