I did most of Sacajawea and Borah last September, and a few weeks ago I completed Sacajawea from Chickenout with Splattski. The NW ridge of Sacajawea is a good challenging scramble. Allow about half of your total allotted time for the Sacajawea portion.
Just past COR and just below Point 11898, find the northwest ridge. Stay close to the top of this ridge on Class 3+ terrain to just past the low point or col of the ridge. After this you can stay on the ridge on mostly solid Class 4 terrain, or drop down slightly on the south side to avoid this. If you drop down more than 100 feet or so, it gets tougher and you'd get off route. One solid Class 4 wall leads to the summit ridge. Retrace your steps back toward Point 11898. From there it's just a slog to get up Borah. Note- there will be no water on this route.