Allow Spectating Other Teams Option does not work, I think it might be dependant on some island settings like team size.
This option:
As the image says you should not be able to spectate the enemy team when you are out of respawns, but this is not the case. You can actually spectate the enemy team which is not expected
These are the settings:
The bug can be observed in this map: 9854-1829-8735
This has been bugged since almost a year I believe I used to have a workaround by setting this option to BATTLE ROYALE, but this option was removed in UEFN. This issue is one of my 2 blocker issues that led me to not release this map.