Nice TR. A group of us were actually up there that weekend but took a really stupid wrong turn off the end of Gentian Ridge which scuppered our plans. Live and learn... I'm 100% going back next summer!
Question: what's the blue route near the area where you gain Gentian Ridge on the Helm side? I really did not enjoy it that section up or down and the blue route looks less steep (maybe?).
Please ignore the blue route near the Gentian/Helm ridge - it shows our pathfinding error - an ascent to the ridge on the very steep and loose scree between Opal Cone and Helm Glacier. You should follow the red route and gain the ridge near Helm Peak and Helm Horn - this route is also steep but it is covered with grass and is easier to ascend. Once you gain the ridge just walk it towards the saddle leading to Gentian Pass. You can see Castle Towers from this saddle and it is pretty obvious how to gain the Polemonium ridge to Castle Towers from there. Please let me know if this helps.