Here's two things I've been doing that speed it up:
Each time you click an obelisk it gives you a medium blue inspiration. During my runs I combine these into a purple insp, and before the AV I use two purples. It's enough def to make it through easily even without full stealth. If anyone is dying on the last part this should help.
Also for clearing groups around the obelisks, you can click the obelisks from super far away, so far away the groups won't even notice you. I wish I had noticed that a long time ago.