Same behavior here on an M1 Mac mini w/Ventura Beta 4 failing to upgrade to Ventura Beta 5 on an external Thunderbolt SSD. Great thought on the security policy—I'm turning off FileVault on the external drive here too. (3 hour estimate—will report back.)

It’s looking promising on my machine after turning off FileVault. Previously, installation would stop after 30 seconds and return me to the login window of beta 4. I’m now looking at an installation progress bar with a “10 minutes remaining” prompt.

No dice—still stuck on beta 4. I’ll update if I have any success.

Same here