Yep, but i'm making this only on full patched games anyway, even pzlib doesn't take that long as precomp
Even when the game got patched in the meantime, in most cases this compression should still work if the game gets not a patch that increase the size of the game by xxxMB (or adds an XXXMB large DLC).
PS: Could be 3,8GB to 4,00GB (without redists).