I lean toward thinking a composer should be continually composing, at least to keep the skills up. I think the initial direction might be clear, but not the details and the composer might not have the skills to realize that vision. They should still get something done, continue composing, and rework the piece later. I believe in inspiration, but I think those are only moments -- There is plenty of grunt work involved and working when you don't really feel like it or want to. I think a composer could work hard on a piece, drop it, and then return later and work hard on it. I believe in the idea of flow -- that the piece will write itself (it's all the other work involved that will get this to happen "by itself") and that if an idea is revised and revised and revised, it may not come out write. If it comes out of the mind complete, it's probably right and the composer knows its right.