Is there a guide anywhere for setting up Fleet to do zero-trust device assurance with Okta, similar to Kolide, etc? I can't even find confirmation online that this is possible, but I thought I'd ask...

There isn't a direct integration for this, but You should be able to use Okta workflows to check policy status in Fleet. Let me check with the team to see if anyone has gotten that up and running.

I'd love to hear about it if so!

I was just pulling this up to share some info, good timing :) We don't have a fully fleshed out workflow for this, but we do have a customer that is using Okta workflows to pull Fleet policy status and allow/deny access based on those.