Figured it out, I think.. scan, byte, 0 = first team, 1 = second team, 3 = observer. Just swap between spectate and a team a few times and rescan 0 vs. 2 or 1 vs. 2 (depending on team) and you'll find it.
The list goes down from 0 to X.. so if there is say, one faction and spectate, there is only 0 and 1. If there are say, 10 factions, it's 0, 1, 2, 3, 4, 5, 6, 7, 8, 9...
So then all you need to do *AFTER* you've spawned is change your faction to another (so if you're on team 0, change yourself to the spectator slot using your memory editor). Then your game should see your allies as an opposing team, and your autoblocking should work versus them. I haven't 100% verified it since I don't have PWMod and don't care to download it... lol. This also has the side effect of removing the crests from allies heads, and putting them over whatever team you're 'fake' on. The server still sees you as on your appropriate team, so this isn't like an instant-team swap or anything.
I did notice with a little finagling I was able to once or twice spawn as say, a Rhodok Spearman on the Vaegir's team by changing my faction while I was waiting to respawn, but it was very inconsistent and obviously very detectable if anybody is paying attention.